SANUR PTY LTD and CITY OF SUBIACO
[2025] WASAT 107
•7 OCTOBER 2025
JURISDICTION : STATE ADMINISTRATIVE TRIBUNAL
ACT: BUILDING ACT 2011 (WA)
PLANNING AND DEVELOPMENT (LOCAL PLANNING SCHEMES) REGULATIONS 2015 (WA)
CITATION: SANUR PTY LTD and CITY OF SUBIACO [2025] WASAT 107
MEMBER: DR S WILLEY, SENIOR MEMBER
MS H PEDERSEN, SESSIONAL MEMBER
HEARD: 28, 29 AND 30 OCTOBER, 2 AND 3 DECEMBER 2024
DELIVERED : 7 OCTOBER 2025
FILE NO/S: DR 178 of 2022
BETWEEN: SANUR PTY LTD
Applicant
AND
CITY OF SUBIACO
Respondent
Catchwords:
Building - Demolition permit - Heritage protected place - Whether development approval necessary prior to grant of demolition permit - Deemed provisions - Whether demolition is urgently necessary as a matter of public safety
Legislation:
Building Act 2011 (WA), s 3, s 10, s 15, s 16, s 21, s 21(1), s 21(1)(j), s 110, s 111(1), s 111(2), s 112(2)(g), s 112(2)(g)(iv), s 119, Pt 2, Div 2
Building Regulations 2012 (WA), reg 19(1)
City of Subiaco Local Planning Scheme No. 5, cl 9(g)
Planning and Development (Local Planning Schemes) Regulations 2015 (WA), Sch 2, cl 1, cl 1A(1), cl 1A(1)(f), cl 9, cl 13, cl 60, cl 61, cl 61(1), cl 61(1)(a), cl 61(1)(b), Pt 1, Pt 3, Pt 7, Pt 8, Pt 9
Planning and Development Act 2005 (WA), s 3(1), s 4, s 87(4), s 119, s 162(1), s 257B, Pt 5, Pt 10, Div 5, Pt 17
State Administrative Tribunal Act 2004 (WA), s 29(1), s 57, s 58
Work Health and Safety Act 2020 (WA)
Result:
The decision under review is affirmed
The application for review is dismissed
Category: B
Representation:
Counsel:
| Applicant | : | Mr J Skinner |
| Respondent | : | Mr T Beckett & Ms M Madvad |
Solicitors:
| Applicant | : | Thomson Geer - Perth |
| Respondent | : | McLeods |
Case(s) referred to in decision(s):
Agricorp Australia Pty Ltd t/as VMS Contractors and Shire of West Arthur [2025] WASAT 40
Citta Hobart Pty Ltd v Cawthorn (2022) 276 CLR 216
Cockatoo Blue Pty Ltd and Metropolitan Central Joint Development Assessment Panel [2017] WASAT 59
Darling Downs Estate Pty Ltd and WAPC [2016] WASAT 76
Harper Investments WA Pty Ltd and Presiding Member of the Metro Inner-North Joint Development Assessment Panel [2023] WASAT 130
Harvis Capital Pty Ltd v Mid-West/Wheatbelt Joint Development Assessment Panel [2020] WASC 205
Housing Commission of New South Wales v Tatmar Pastoral Co Pty Ltd (1983) 3 NSWLR 378
Jones v Dunkel [1959] HCA 8; (1959) 101 CLR 298
Landcorp and City of Stirling [2011] WASAT 202
Lombardi Investments (WA) Pty Ltd and City of Cockburn [2009] WASAT 65
Newco Mills Pty Ltd and Presiding Member of the Metro Outer Joint Development Assessment Panel [2021] WASAT 160
Presiding Member of the Southern Joint Development Assessment Panel v DCSC Pty Ltd [2018] WASCA 213; (2018) 54 WAR 89
Sanur Pty Ltd and City of Subiaco [2021] WASAT 90 (S); (2021) 103 SR (WA) 67
Sanur Pty Ltd and City of Subiaco [2021] WASAT 90; (2021) 103 SR (WA) 1
The Match Group v Metropolitan South West Joint Development Assessment Panel [2014] WASCA 50; (2014) 2000 LGERA 227
Zorzi and Town of Cambridge [2025] WASAT 77
Contents
Introduction
Issues
Jurisdiction
Relevant background
The Building
Events in the 1980s
Events in 2021
Cracking in the brickwork
Hay Street is closed and the City obtains its own structural engineering advice
Applications to demolish and redevelop
The City issues Emergency Building Orders
A temporary support structure is agreed
Sanur No 1
Hay Street is reopened
Events since 2021
The City obtains further structural engineering advice
The City issues a further building order and an order for a grout trial is agreed
The Application
Building Order Review
Further applications for development approval
Conduct of the Review
The current state of the Building façade
Legislative scheme
Building Act
PD Act
LPS 5
Construction of LPS 5
Case overview: Respondent
Case overview: Applicant
Issue 1: Whether the Building is in an active state of rotation
Respondent's engineering evidence
Dr Katz
Mr Marra
Applicant's engineering evidence
Mr MacMillan
Mr MacKerron
The Joint Report
Summary of the engineering evidence
The surveying evidence
Disposition of Issue 1: the Building is not in an active state of rotation
Issue 2: Whether demolition is urgently necessary as a matter of public safety
Structural engineering evidence: my findings
While there has been some historic rotation; the Building is stable
Why I prefer and accept the evidence of Dr Katz
Why I do not accept Mr MacMillan's evidence
Meaning of the phrase 'urgently necessary' for 'public safety'
Disposition of Issue 2: demolition of the Building is not necessary nor urgent
The reviewable decision does not extend to making a determination as to whether the Building can, in fact, be saved
Conclusion
The effect of this decision
SESSIONAL MEMBER PEDERSEN (dissenting)
Background and Legislative framework
Is demolition urgently necessary for public safety?
Evidence
Applicant's engineering evidence
Mr MacMillan
Mr MacKerron
Respondent's engineering evidence
Dr Katz
Mr Marra
Consideration
Why I am satisfied that there is a risk of collapse that needs to be urgently addressed
Why I believe demolition is the only available course of action
Why I believe that failure constitutes a risk to public safety
Additional considerations
Orders
REASONS FOR DECISION OF THE TRIBUNAL:
Introduction
These reasons deal with the latest iteration of the Sanur dispute; a saga that has played out over a number of years and in a number of forums, including the Tribunal in Sanur Pty Ltd and City of Subiaco (Sanur No 1).[1] At the heart of the dispute is Sanur Pty Ltd's (Applicant or Sanur) desire to demolish the building it owns at 424 - 436 Hay Street, Subiaco (Building).
[1] Sanur Pty Ltd and City of Subiaco [2021] WASAT 90; (2021) 103 SR (WA) 1 (Sanur No 1); see also Sanur Pty Ltd and City of Subiaco [2021] WASAT 90 (S); (2021) 103 SR (WA) 67 (Sanur No 2).
In this proceeding, the Applicant contends that the demolition of the Building is 'urgently necessary' as a matter of 'public safety'. The need to demolish the Building urgently, or at all, is contested by the City of Subiaco (City or Respondent). The City instead contends the Building can be restored and repaired.
Sanur seeks to review the City's decision to refuse its application for a demolition permit (Application) under the Building Act 2011 (WA) (Building Act). The City refused the Application on the basis that it was incomplete, on account of Sanur not having first obtained development approval for the demolition 'works' under the City of Subiaco Local Planning Scheme No. 5 (LPS 5).
Because development approval has not been obtained under LPS 5, the City contends that the Application does not comply with s 21(1)(j) of the Building Act. Section 21(1)(j) requires an applicant for a demolition permit to be accompanied by each authority required for the demolition work pursuant to prescribed 'written laws' which, relevantly, includes approvals required under the Planning and Development Act 2005 (WA) (PD Act).[2]
[2] Building Regulations 2012 (WA), reg 19(1).
Like all local planning schemes, LPS 5 includes the 'deemed provisions'.[3] The contest in this matter centres on the application of cl 61 of the deemed provisions, which identifies a range of works that do not require development approval, provided certain conditions are satisfied.[4] Relevantly, item 18 of the Table in cl 61(1) provides that demolition of the Building (which is a 'heritage protected place' under LPS 5) may be undertaken without obtaining a development approval, if such works are 'urgently necessary' as a matter of, relevantly, 'public safety'.
[3] The deemed provisions are made pursuant to s 257B of the PD Act.
[4] More precisely, item 18 of the Table in cl 61(1).
Accordingly, this review is directed towards, in effect, an assessment as to whether the demolition of the Building is urgently necessary as a matter of public safety (Review).
Because the members that constitute the Tribunal in this proceeding have reached different conclusions, the Review is to be resolved in accordance with s 58 of the State Administrative Tribunal Act 2004 (WA) (SAT Act). The effect of s 58 is that where the opinions of the Tribunal members are equally divided, the Review is to be determined in accordance with the opinion of the presiding member. By reason of s 57 of the SAT Act, I am the presiding member. However, Sessional Member Pedersen's reasons are published separately as a matter of transparency.
For my reasons that follow, I have determined that the correct and preferable, at the time of the decision on review, is to dismiss the Review. That is so because, I find, the demolition of the Building is not urgently necessary. However, I also find that it is prudent, indeed pressing, that remedial works are undertaken as quickly as is possible, or the Building should otherwise be demolished. This entire matter has already dragged on for far too long.
Sessional Member Pedersen takes a different view. In her view, the evidence has evolved significantly since the City made its initial decision such that the Review should be upheld. Further, Sessional Member Pedersen considers that it is prudent, indeed pressing for the works currently prescribed under the Building Order Review to be reviewed in the light of the risks identified.
Issues
The parties could not agree on the precise formulation of the issues that the Tribunal is required to determine. However, it is not in dispute that, however formulated, our task is to assess whether the application for a demolition licence complies with the requirements of s 21(1) of the Building Act, notwithstanding the absence of a development approval under LPS 5.
If we find, consistent with Sanur's case, that the Application complies with s 21(1) of the Building Act, it is not in contest that the demolition permit must be granted.
Because this Review is, in effect, an assessment of whether demolition of the Building is urgently necessary as a matter of public safety, it is that issue which is the focus of my reasons.
My reasons address the following issues:
(1)Whether the Building is in an active state of rotation; and
(2)Whether demolition of the Building is urgently necessary as a matter of public safety.
Jurisdiction
The Application arises in the Tribunal's review jurisdiction. Accordingly, our task is to make the correct and preferable decision at the time of the decision on the review. The Review is to be conducted as a hearing de novo. Neither party bears any legal or practical onus.
In these reasons, where I state that I am satisfied as to the existence of a fact, this means that I am satisfied on the balance of probabilities that the fact has been proved.
Relevant background
The relevant background of the matter is largely uncontested and spans many pages of the Respondent's Substituted Statement of Issues, Facts and Contentions,[5] as well as the Applicant's Statement of Issues, Facts and Contentions.[6]
[5] Exhibit 2.
[6] Exhibit 4.
An overview of that history, as is relevant, follows.
The Building
The Building was constructed in about 1921 and comprises a row of single storey commercial buildings with intact shop fronts, each of which retain their original recessed entrance doors. A framed canopy with bullnosed edging runs along its length. This canopy was not part of the original building but was observed in a (May 1989) report by Pritchard & Francis[7] (Pritchard & Francis Report) as a 'cantilevered awning over the footpath' that has 'apparently remained in satisfactory condition for many years'.[8]
[7] Pritchard & Francis Pty Ltd Consulting Engineers, 'Report on Cracking of Dividing Walls to Shops at 424 Hay Street, Subiaco', 1989.
[8] Exhibit 2, paras 13 to 17.
The Building originally included eight returning walls (two end walls and six intermediate) separating seven tenancies. However, over time three of the dividing walls were removed, although two of the three walls remain above the roof line and are supported on a beam.[9]
[9] Exhibit 1, paras 19 and 20.
Sanur purchased the Building in December 1985 and undertook substantial renovation and repair works in 1986.
Events in the 1980s
Due to major trench excavations by public agencies on the adjacent footpath, substantial cracking appeared in the Building's dividing walls in the late 1980s. The Pritchard & Francis Report noted the significance of '… cracks in the wall above the ceiling line which are more like gaps (i.e. 50 mm or 2 inches wide)' and ultimately concluded that the cracks were not new, but old cracks which had re-opened.[10]
[10] Exhibit 1, paras 26 and 27.
The Pritchard & Francis Report then noted that cracking in the walls was typically associated with differential settlement. The dividing walls, although supported by poor ground conditions, are unlikely to crack and settle differentially as a result of their own weight, or that of the roof. However, the front parapet wall (weighing approximately 10 tonnes per pier) dropping as a point load right at the end of the dividing wall, and the lateral load imposed by the tied back awning, present a logical explanation for the cracking that is evident, with larger cracks being present near the top of the wall, rather than near the floor.[11]
[11] Exhibit 1, para 28.
With respect to the cantilevered awning, the Pritchard & Francis Report explained that it was a separate, but related, matter. The report commented that the awning remained in good condition after many years, together with some calculations and assessing of its present support, led to a conclusion that it is likely to remain in a stable condition, despite the cracking in the walls. It was also noted, however, that there were 'no guarantees'.[12]
[12] Exhibit 1, para 29.
The Pritchard & Francis Report recommended chemical grouting be undertaken at 'the ends of the dividing walls under the location of the large parapet point load'. While the Respondent stated that these grouting works were never undertaken,[13] the Applicant provided itemised details of the works that did include a line item for grouting.[14] Whether the grouting work that was recommended in the Pritchard & Francis Report was ever carried out cannot be resolved by the Tribunal, but in any event, has little bearing on the current dispute.
[13] Exhibit 1, para 30.
[14] Exhibit 4, para 12 and Exhibit 5, item 27.
The Pritchard & Francis Report further recommended the installation of 2 to 3 metre steel struts into the roof space to increase the stability of the awning and to assist in reducing the risk of further cracking.[15]
Events in 2021
Cracking in the brickwork
[15] Exhibit 1, para 31.
In 2021, sections on the internal dividing walls were removed to expose some of the underlying brickwork. Some cracking in the brickwork was revealed. An engineer's report suggested that cracking in the plaster of one of the dividing walls in Tenancy 7 was 0.3 mm. Where the plaster had been removed, cracking to a width of 20 - 30 mm was revealed in the underling masonry wall. In Tenancy 2, cracking of between 20 and 40 mm was observed in the masonry wall. A hairline crack of approximately 0.2 to 0.3 mm was also observed.[16]
[16] Exhibit 1, para 35.
Following a structural site inspection by the Applicant and its engineer (ARUP) on 28 January 2021, the Applicant emailed the City to advise that:
(a)major structural issues had been detected in the Building;
(b)ARUP are finalising an urgent report; and
(c)a meeting between the City and the Applicant would be urgently arranged.[17]
[17] Exhibit 1, para 38.
ARUP issued its report on 3 February 2021 (ARUP Report)[18] and advised that there were cracks in the dividing walls that 'are structurally significant' measuring up to 100 mm wide. The ARUP Report noted that the front façade was leaning over the adjacent footpath by as much as 160 mm.[19]
[18] Exhibit 2, tab 9.
[19] Exhibit 1, paras 41 and 42.
The ARUP Report stated that, absent any other information, the Hay Street elevation was 'at risk of uncontrolled collapse', especially in the event of an unexpected load including a minor earthquake or high winds.[20] ARUP's recommended 'immediate actions' included: (a) securing the Building and to minimise entry; and (b) that adjacent footpath and pavement areas be cordoned off to minimise risk.[21]
[20] Exhibit 1, para 43.
[21] Exhibit 1, para 44.
On 3 February 2021, the Applicant, through its solicitors, also signalled its intent to seek to demolish the Building and to redevelop the site.[22]
[22] Exhibit 1, para 46.
On 4 February 2021, ARUP issued a further report in relation to the adjacent 440 Hay Street. ARUP considered that 440 Hay Street was also unsafe due to cracking in the external walls.[23]
Hay Street is closed and the City obtains its own structural engineering advice
[23] Exhibit1, paras 47 - 48.
On 5 February 2021, the northern footpath and parking bays in front of the Building and 440 Hay Street, as well as both lanes of Hay Street (between Catherine Street and Rokeby Road) were closed. Traffic was reduced to a single lane.[24]
[24] Exhibit 1, paras 51, 52 and 57.
The Respondent then engaged its own structural engineer (Structerre), which advised that the Building was not stable and neither was 440 Hay Street. An exclusion zone was recommended, and from 13 February 2021 implemented, pursuant to Australian Standard (AS) 2601-2001; The demolition of structures (AS 2601).[25]
[25] Exhibit 1, paras 55 and 56.
On 14 February 2021, ARUP recommended that the Building, together with 440 Hay Street be demolished, so as to 'eliminate the ongoing risks of collapse'.[26]
[26] Exhibit 1, para 59.
At a Special Council Meeting on 15 February 2021, the Council resolved to urgently engage a structural engineer (independent of the structural engineers that have reported to date) with suitable heritage and conservation experience. The engineer was to determine (and report on):[27]
… whether it is possible and the methods by which parts of the Building and 440 Hay Street which preserve the heritage values of the buildings can be stabilised, remediated, made safe and retained in situ or deconstructed … with a view to other parts of the buildings not required to stabilise or retain the façades being demolished.
[27] Exhibit 1, para 60.
To this end, the City engaged Quoin Structural & Heritage Engineers (Quoin) to report on the matters outlined in the Council resolution.
Quoin issued its report on 25 February 2021 (Quoin Report).[28] The Quoin Report stated, relevantly:[29]
… There is a low risk that part of the façade of 424-436 Hay Street may fail if subject to an adverse environmental event (high wind, earth tremor). Therefore, the façade should be propped as soon as is practicable to maintain its stability. Further survey measurements and investigation should be undertaken to determine whether or not the façade can be stabilised and remediated. From a heritage perspective, it is reasonable to assert that there is a strong likelihood that the façade can be remediated and retained.
[28] Exhibit 2, tab 24.
[29] Exhibit 1, para 67.
On 26 February 2021, the City sent the Applicant a copy of the Quoin Report and set out its key findings.
Applications to demolish and redevelop
On 22 February 2021, the Applicant submitted an application for development approval under LPS 5, seeking permission to demolish the Building (Demolition DA).
On 2 March 2021, at a Special Council Meeting, Council identified it had 90 days to consider the development application. The Council resolved to:
(a)undertake public consultation;
(b)refer the application to the Western Australian Planning Commission (WAPC) for comment; and
(c)assess the application in accordance with the City's planning framework.
The Council also adopted further resolutions, including to:
(a)appoint a qualified consultant to design and install an appropriately rated hoarding fronting the Building; and
(b)issue a Building Order in relation to the Building to:
(i)design and install a temporary support structure;
(ii)provide the City with written confirmation by a suitably qualified expert that the temporary support structure has been designed and installed and is fit for purpose; and
(iii)complete such works within 28 days.
On 26 March 2021, the Applicant lodged an application for a demolition permit for the Building with the City.[30] That application was deemed refused and, on 14 April 2021, the Applicant commenced a review for the Building (relevantly, DR 70 of 2021).
[30] Exhibit 1, para 93.
On 27 May 2021, the City refused the Demolition DA. However, the Applicant did not seek, and has never sought, a review of the Demolition DA.
Sanur No 1, which is discussed further below,[31] was then heard and determined.
The City issues Emergency Building Orders
[31] Refer [52] to [58] below.
On 3 March 2021, the City, in its capacity as a permit authority, issued to the Applicant an Emergency Building Order under s 110 and s 111(2) of the Building Act, requiring the Applicant to:[32]
(a)Within 14 days of the service of this Order, arrange for a suitably qualified structural and heritage engineer to design a temporary support structure to support the Hay Street façade of the Building which can be installed through the awning on the Hay Street side of the Building and provide a copy of the design to the City; and
(b)Within 28 days of the service of this Order, install the temporary support structure referred to in paragraph (a) above and provide to the City written confirmation by a suitably qualified structural and heritage engineer that the temporary support structure has been installed as designed and is fit for purpose.
[32] Exhibit 1, para 73.
The Applicant lodged an application for review in relation to the City's decision to issue the Emergency Building Order (being DR 38 of 2021).[33] The Applicant's case was that the Building cannot be made safe.
[33] Exhibit 1, para 74.
On 4 March 2021, the Application sought a stay of the Emergency Building Order and also an urgent hearing in relation to Hay Street (which had been closed and which the City planned to reopen).[34]
A temporary support structure is agreed
[34] Exhibit 1, paras 75, 77 and 78.
The parties ultimately agreed, at a directions hearing on 5 March 2021 in DR 38 of 2021, that a temporary support structure for the Building façade would be installed and:[35]
.… that the respondent would procure 'the design of a temporary support structure to support the Hay Street façade of the building at 424436 Hay Street, Subiaco that is acceptable to the respondent'.
[35] Exhibit 1, para 82.
On 10 March 2021, Hay Street was partially reopened as ARUP agreed that the neighbouring building at 440 Hay Street was not at imminent risk of collapse, reducing the exclusion zone to that required by the single storey Building the subject of the Review.
On 17 March 2021, the Respondent issued a substituted Emergency Building Order in accordance with the consent position reached at the directions hearing on 5 March 2021.
Sanur No 1
On 17 March 2021, the Respondent issued a heritage conservation notice on the Applicant in relation to the Building.
The Applicant sought review of that decision (being DR 51 of 2021) being Sanur No 1, the final hearing for which was between 14 and 16 April 2021.[36]
[36] Together with matters DR 50 of 2021 and DR 52 of 2021 which related to 440 Hay Street; Exhibit 1, para 95.
Sanur No 1 involved a review of decisions made by the City to make building orders, and to issue heritage conservation notices, in relation to the Building and 440 Hay Street. The building order, as is relevant, required the installation of a temporary support structure. Sanur instead sought orders requiring the building order to be varied so as to require the Building to be demolished.
The heritage conservation notices, which required remedial works to be undertaken, were set aside because the Tribunal was not satisfied that the Building had not been properly maintained for the purposes of cl 13 of the deemed provisions.
In Sanur No 1, the Tribunal:
(a)set aside the heritage conservation notice for the Building;
(b)affirmed the building orders for the Building; and
(c)varied the date for compliance with the Emergency Building Order.
In its published reasons, the Tribunal considered that the statutory requirements to make a building order pursuant to s 112(2)(g) of the Building Act were met because it was satisfied that the façade wall was 'in a dangerous state'. However, the Tribunal was also satisfied that the temporary support structure provided for in the building order would 'shore up' the façade of the Building for the purposes of s 112(2)(g)(iv).[37]
[37] Sanur No 1 [66].
The Tribunal had before it survey evidence and, based on that evidence, concluded that the Building façade was not moving.[38] The Tribunal also considered evidence in relation to 'tell-tales'[39] that had been installed over cracks in the dividing walls. However, the Tribunal concluded that any movement in the dividing walls had not translated into any movement of the façade.[40]
[38] Sanur No 1 [144].
[39] Being a device to measure or detect cracks in buildings.
[40] Sanur No 1 [146].
The Tribunal's ultimate conclusion was that the correct and preferable decision was to require the Applicant to install the temporary support structure.[41] The Tribunal rejected the Applicant's argument that it had power to instead set the building order aside with a new building order requiring demolition of the Building.[42]
[41] Sanur No 1 [169].
[42] Sanur No 1 [161].
The Applicant then applied to suspend the order pending the determination of its application for a demolition permit. Following further submissions, the Tribunal handed down a supplementary decision in which it refused to suspend the operation of the Emergency Building Order.[43]
Hay Street is reopened
[43] Sanur No2.
The Applicant applied to extend the time for compliance with the Emergency Building Order which was granted by the City. The temporary support structure was eventually erected in mid-late August 2021. On 27 August 2021, Hay Street was fully reopened.
On 30 July 2021, the Applicant was given leave to withdraw DR 70 of 2021, and the matter was withdrawn.
Events since 2021
On 14 and 15 February 2022, the Building façade was surveyed eight times whilst resurfacing works were taking place on Hay Street and Catherine Street in Subiaco. The surveys detected no movement in the façade.
The City obtains further structural engineering advice
In early 2022, the Respondent engaged Keystone Structural Engineers (Keystone Structural) to assess the structural condition of the Building and to advise whether it could be structurally repaired or remediated, including the works required as part of any repair or remediation.
On 15 May 2022, Dr David Katz (now at Keystone Structural together with Mr Geoff Gaynor) conducted a site inspection of the Building. Keystone Structural subsequently issued a report (Keystone Structural Report) on 9 August 2022 which included the following conclusion:[44]
Our assessment concluded that the structural integrity of the façade and the dividing walls was compromised, but could be reinstated by repairing the cracks, improving the material restraint to the façade and stiffening the foundation material.
[44] Exhibit 1, para 126.
The Keystone Structural Report set out a list of recommended works to reinstate the structural integrity of the façade.
The City issues a further building order and an order for a grout trial is agreed
On 12 August 2022, the Respondent issued a notice to the Applicant pursuant to s 111(1) of the Building Act that it proposed to issue a building order that, in substance, required it to undertake the measures recommended in the Keystone Structural Report. Subsequently, on 15 September 2022, the City issued a building order which required the following:
(1)A full geotechnical investigation to be carried out. This was carried out by Galt Geotechnics (Galt) which produced the Galt Geotechnical Report.
(2)Excavation to measure the footing sizes for the piers and dividing walls, with a structural engineer to assess the findings and specify the requirement for stiffening the footings, for example by grout injection.
BG&E undertook the structural assessment, which was provided, together with the Galt Geotechnical Report, on 20 September 2022. BG&E considered that any works on the Building were high risk and recommended demolition as the only safe and feasible option.
The Application
On 27 September 2022, the Applicant lodged the Application which the City refused on 26 October 2022. The City's decision is the basis for the Review (DR 178 of 2022).
On 28 September 2022, the Applicant's lawyer emailed the Respondent outlining the claimed exemption from development planning approval and referencing a letter sent the same day to the Applicant and Respondent from the Secretary of the WAPC. The WAPC expressed the view that, having regard to the BG&E report, the demolition works were urgently necessary for public safety and therefore that planning approval was not required.
Building Order Review
On 13 October 2022, the Applicant sought a review of the building order (DR 180 of 2022) (Building Order Review).
The Building Order Review and the Review were case managed together for an extended period. A number of further investigations and reports were carried out in 2023 in the context of both proceedings. These included:
(a)On 18 January 2023, a joint statement by Mr Donald MacMillan of BG&E and Dr Katz of Keystone Structural;
(b)On 21 January 2023, a joint statement by Mr Owen Woodland of Galt and Mr Terry Waters of Local Geotechnics;
(c)On 4 August 2023, a joint statement by Mr Woodland of Galt and Mr Waters of Local Geotechnics (Geotechnical Joint Statement);
(d)On 29 August 2023, a joint statement by Mr Frank van de Ven of Shorepile and Mr Derek Craig of Advanced Ground Solutions, both of whom are grout injection contractors (Grouting Contractor Joint Statement);
(e)On 29 August 2023, a report to the Applicant titled '424-436 Hay Street - Recent Site Investigations' (BG&E August 2023 Report); and
(f)On 6 September 2023, an updated joint statement by Mr MacMillan of BG&E and Dr Katz of Keystone Structural (Engineering Joint Statement).
On 14 December 2023, the parties agreed to vary the building order the subject of the Building Order Review; to instead require the Applicant to carry out a series of steps as a prerequisite to the grouting injection trial works to a specified area of the Building. The purpose of the trial was to determine whether grouting would be an adequate remedial solution.
On 19 January 2024, the Applicant submitted a report to the Respondent, in compliance with paragraph 4 of the Varied Building Order, which required additional testing, reporting and notifications with respect to the location of the grouting injection trial.
On 2 February 2024, the Applicant informed the Respondent that Galt and BG&E were unable to provide a plan and method statement for the safe execution of the works as required by paragraph 5 of the Varied Building Order. BG&E considered that the grouting injection trial testing was unsafe to carry out.
Neither the City, nor the Applicant, have taken any further action as specified in the Varied Building Order that was agreed in the Building Order Review.
Further applications for development approval
The Applicant has made two further approval applications for redevelopment which, if approved, would require the Building to be demolished, namely:
(a)an application for development approval lodged with the State Development Assessment Unit in July 2020, made pursuant to Pt 17 of the PD Act (SDAU Application); and
(b)an application for development approval dated 15 September 2023, made to the Metro Inner-North Joint Development Assessment Panel (JDAP Application).
In making both the SDAU Application and the JDAP Application, the Applicant placed some reliance on its assertion that the Building was in a dangerous state and ought to be demolished.
SDAU Application
The SDAU Application involved the redevelopment of the site (requiring the demolition of the Building) for a 12 storey commercial development which included the adjacent Burley Lane (Lot 60 on Plan 2442) and No. 1 (Lot 500) Seddon Street. Burley Lane is owned by the City in fee simple.
The SDAU application was formally withdrawn on 9 May 2024.
JDAP Application
The JDAP Application was also premised on the Building being demolished to be replaced by a single and two storey commercial development. The JDAP Application was initially deferred (becoming DR 7 of 2024) and ultimately refused by the Metro Inner-North Joint Development Assessment Panel.
DR 7 of 2024 was withdrawn on 28 August 2024.
Conduct of the Review
One might think, because the Review is pressed as a matter of public safety, that it would have been urgently progressed to enable a rapid resolution. However, that is not at all how this matter has been conducted by the parties.
As has been set out above, the Review was lodged on an urgent basis in October 2022. Unsurprisingly, an expedited hearing was initially requested, and the matter was urgently listed for final hearing in February 2023.
An expedited final hearing did not proceed due to the unavailability of relevant experts. The matter then drifted somewhat; so much so that in June 2023, the Respondent applied for the Review to be dismissed for want of prosecution due to the Applicant not diligently prosecuting its case. In July 2023, a costs order was made in favour of the Respondent.
The matter was again listed for hearing in August 2023 to enable the issues as between the parties to be clarified. The August 2023 hearing did not proceed, and that hearing was listed again for September 2023. The matter was ultimately listed for final hearing in November 2023.
However, in October 2023, the Applicant wrote to the Tribunal advising that it sought to withdraw the Review. This was because the parties had agreed to undertake the grout trial in the Building Order Review.
In its letter to the Tribunal seeking to withdraw the Review, the Applicant accepted that until the outcome of the grout trial is known, 'it cannot be determined with certainty whether or not the demolition of the building is "urgently necessary for public safety'' '.
In further support of its application to withdraw, the Application relied on its JDAP Application, which by then had been lodged, which, if approved, would authorise the demolition of the Building.
However, the Respondent did not agree to withdraw the Review for a range of reasons, including its costs thrown away and the fact that that in making the withdrawal application, the Applicant expressly reserved its right to relitigate the question again. The final hearing for November 2023 was again vacated.
In January 2024, the Applicant again applied to withdraw the Review. That application was withdrawn in April 2024.
In May 2024, the matter was listed for a final hearing in October 2024.
The current state of the Building façade
It is not in contest that:
(a)The Building façade has:
(i)a lean of up to 160 millimetres towards Hay Street. The brick parapet wall has an outward bow associated with this lean;
(ii)not moved (outside the tolerance of the survey equipment) since survey measurements were recorded, commencing on 23 January 2023.
(b)At some unknown point, before the surveying of the façade commenced, Pier 7 appeared to have rotated 0.043 degrees over a 23-month period. Other than Pier 7, the remaining façade has not undergone measurable movement (outside the survey tolerance) since the surveying commenced in February 2021.[45]
[45] Exhibit 1, para 143.
Legislative scheme
Building Act
Demolition permits are provided for in Div 2 of Pt 2 of the Building Act. In general terms, a person must not undertake 'demolition work' unless a demolition permit is in effect, or the demolition works are otherwise authorised.[46]
[46] Building Act, s 10. Demolition work relevantly means the 'demolition, dismantling or removal of a building or an incidental structure': Building Act, s 3.
An application for a demolition permit may be made pursuant to s 15 of the Building Act and must include the requirements set out in s 16. A permit authority may request further information within 21 days.
Demolition permits are determined pursuant to s 21 of the Building Act. In short compass, the permit authority is required to grant a demolition permit if the requirements set out in the subparagraphs of s 21(1) are satisfied. Section 21(1)(j) requires an applicant to obtain, in relation to the demolition work, each authority under a written law that is prescribed.
Regulation 19(1) of the Building Regulations 2012 (WA), provides that, for the purposes of s 21(1)(j), if the demolition work is 'development' as that term is defined in s 4 of the PD Act, then each approval required under the PD Act is prescribed.
Section 119 of the Building Act provides that a person who applies for a demolition permit may review a decision of the permit-authority to refuse to issue a demolition permit.
PD Act
The purposes of the PD Act include: 'to provide for an efficient and effective land use planning system' and to 'promote the sustainable use and development of land'.[47]
[47] PD Act, s 3(1).
Part 10 of the PD Act deals with subdivision and development control. Division 5 of Pt 10 deals with development control. The effect of s 162(1) is that where a planning scheme applies, 'development' is not to be commenced or carried out without a development approval, authorising that development, being obtained.
LPS 5 is a local planning scheme made pursuant to Pt 5 of the PD Act and commenced on 21 February 2020. LPS 5 has effect, 'as if enacted', by the PD Act.[48]
LPS 5
[48] PD Act, s 87(4).
The aims of LPS 5 include, relevantly, to 'promote and safeguard the special character and cultural heritage of the City' by, relevantly; '(i) identifying, conserving and enhancing those places which are of significance to the City's cultural heritage'; and to '(iii) protect and enhance local heritage and character …'.[49]
[49] LPS 5, cl 9(g).
The deemed provisions are made pursuant to Pt 15 of the PD Act. The deemed provisions are given effect by s 257B of the PD Act and are contained in Sch 2 to the Planning and Development (Local Planning Schemes) Regulations 2015 (WA).
Part 1 of the deemed provisions defines 'works' to include 'demolition'. Part 7 of the deemed provisions sets out the circumstances in which development approval is required. The effect of cl 60 of the deemed provisions is that development approval under Pt 8 [sic Pt 9] is required to either/or undertake 'works' or use land unless the proposed development is exempt from requiring approval by reason of cl 61.
Clause 61(1) includes a Table which sets out classes of works which are exempt from requiring development approval. The effect of the Table in cl 61(1) is that if the works are of a kind referred to in Column 1 and any conditions set out in corresponding Column 2 are satisfied, development approval is not required for the works in question.
Item 18 of the Table provides as follows:
18.
Works that are urgently necessary for any of the following —
(a) public safety;
(b) the safety or security of plant or equipment;
(c) the maintenance of essential services;
(d) the protection of the environment.
The works are not located in a heritage-protected place of a kind referred to in cl 1A(1)(a), (b) or (d).
Clause 1A(1) of the deemed provisions defines a 'heritage-protected place' to mean a place:
(a)that is entered in the State Register of Heritage Places under the Heritage Act 2018 section 42; or
(b)that is under consideration for entry into the State Register of Heritage Places as described in subclause (2); or
(c)that is the subject of an order under the Heritage Act 2018 Part 4; or
(d)that is the subject of a heritage agreement that has been certified under the Heritage Act 2018 section 90; or
(e)that is included on a heritage list as defined in clause 7; or
(f)that is within a heritage area as defined in clause 7.
Part 3 of the deemed provisions deals with heritage protection and establishes 'heritage areas', 'heritage lists' and 'places'.
Consistent with the Tribunal's reasons in Sanur No 1,[50] the parties agree that the Building is located within a 'heritage area' (known as the Rokeby Road and Hay Street Conservation Area) pursuant to cl 9 of the deemed provisions.
[50] Sanur No 1 [72] - [91].
Because the Building forms part of a heritage area it is, perforce of cl 1A(1)(f), a 'heritage-protected place' under the deemed provisions.
Accordingly, pursuant to item 18 of the Table, the exemption from obtaining development approval may apply if the demolition of the Building is 'urgently necessary' for, in this instance, 'public safety'.
Construction of LPS 5
LPS 5 is subsidiary legislation and is to be construed in accordance with the orthodox canons of construction. In Newco Mills Pty Ltd and Presiding Member of the Metro Outer Joint Development Assessment Panel (Newco Mills),[51] Pritchard P set out the following analysis on the correct approach to the construction of a scheme:
31The construction of a local planning scheme, which constitutes subsidiary legislation, involves determining the objective meaning of the terms used, by the application of recognised rules of interpretation to the text, understood as a whole and in its context. The meaning must emerge from the statutory text, understood in its context, but also having regard to the statutory purpose being pursued.
32It is well established that planning schemes should be construed broadly rather than pedantically, and with a sensible practical approach. That approach recognises that planning schemes are not usually drafted by parliamentary counsel and are often expressed in terms which lack the precision of a statute. That approach also recognises that the terms of planning schemes are regularly referred to, often without the assistance of professional legal advice, by planners, government officials, landowners and prospective landowners, to identify the permissible uses of land to which a scheme applies. For that reason, the Court of Appeal has cautioned against placing a counter-intuitive judicial gloss on the plain language of planning schemes because to do so would reduce the capacity of the range of persons who use such schemes to comprehend their meaning. Nevertheless, the exercise of construction remains one of identifying the objective meaning from a consideration of the legislative text, understood as a whole and in the context in which, and purpose for which, it was enacted.[52]
[51] Newco Mills Pty Ltd and Presiding Member of the Metro Outer Joint Development Assessment Panel [2021] WASAT 160 (Newco Mills) [31] - [32].
[52] Internal citations omitted.
In terms of construing local planning schemes consistent with their legislative purpose; it is trite to observe that that purpose is a town planning purpose.[53]
[53] Agricorp Australia Pty Ltd t/as VMS Contractors and Shire of West Arthur [2025] WASAT 40 [116]; Landcorp and City of Stirling [2011] WASAT 202 [44].
Case overview: Respondent
The Respondent does not consider that the demolition of the Building is 'urgently necessary' for 'public safety'.
The phrases 'urgently necessary' and 'public safety' are not defined, nor are they terms of art. They therefore should be interpreted in accordance with their ordinary meaning. The Macquarie Dictionary Online includes the following definitions:
publicadjective 1. of, relating to, or affecting the people as a whole or the community, state or nation: public affairs.
safetynoun 1. the state of being safe: freedom from injury or danger.
In this context, works that are 'for … public safety' are works that will keep members of the community free from injury or danger. That is to say, the works must mitigate or eliminate a potential risk of injury or danger to members of the community.
The Macquarie Dictionary Online defines 'necessary' to mean as follows:
necessaryadjective 1. that cannot be dispensed with: a necessary law
The use of the word 'necessary' in the context of the phrase 'urgently necessary for … public safety' therefore connotes works which are indispensable for ensuring public safety. That is, it is submitted, the works must be the only way that a potential risk of injury or danger to members of the community can be mitigated or eliminated.
The Macquarie Dictionary Online gives the first meaning of 'urgent' as follows:
urgent adjective 1. pressing; compelling or requiring immediate action or attention; imperative [with 'urgently' being the adverb for 'urgent'].
The use of the term 'urgently necessary' in the context of the phrase 'urgently necessary for … public safety' connotes that the works must happen immediately and without delay in order to ensure public safety. Furthermore, the demolition works are the only way to ensure public safety.
The Respondent submits that the purpose of item 18 can be inferred from the ordinary meaning of the words used 'urgently necessary for … public safety'.
The general position, as provided for in cl 60 of the deemed provisions, is that demolition works are 'works' that require development approval. That general position accords with the purpose of the PD Act, in that it promotes the sustainable use and development of land.
Item 18 provides for an exemption from the general position, where such works are required to ensure public safety where:
(a)the only way to ensure public safety is to undertake the works; and
(b)the works need to be done without delay to ensure public safety.
That is to say, the effect of item 18 is that ensuring public safety will be given priority over the purpose of promoting sustainable use and development of land, only where the two conditions set out above are satisfied.
As a result, the exemption will not apply where:
(a)public safety can be ensured other than by undertaking the demolition works, as the works would not then be 'necessary' for public safety; and
(b)if the works do not need to be undertaken without delay in order to ensure public safety, as the works would not then need to be undertaken 'urgently'.
The Respondent submits that item 18 creates a narrow exception to the requirement to obtain development approval which is only enlivened in circumstances where public safety cannot be ensured if the development approval process is followed.
The resolution of the question of whether the demolition of the Building is 'urgently necessary for … public safety' depends on whether:
(a)there is a risk of imminent collapse of the façade notwithstanding the temporary support structure; and
(b)if there is an imminent risk of collapse, is there any alternative to demolition that would ensure public safety.
On the question of whether there is an imminent risk of collapse, the Respondent submits that the Building façade is structurally compromised but stable.
Furthermore, the Tribunal should accept the conclusions of the Quoin Report (prepared before the temporary support structure was installed) that:[54]
(a)while '[t]he masonry [façade of the Building leans] southwards towards Hay Street … the [façades] are not at immediate risk of collapse'; and
(b)there 'is a low risk that part of the [Building façade] may fail if subject to an adverse environmental event (high wind, earth tremor). Therefore, the façade should be propped as soon as is practicable …'.
[54] Exhibit 2, page 422.
The small risk of partial collapse, in the context of an adverse environmental event, has now been mitigated by the presence of the temporary support structure.
Accordingly, there is no need to demolish the Building to ensure public safety.
Even if the Tribunal finds that there is an imminent risk the façade will collapse, it does not necessarily follow that demolition is urgently necessary. That is because, the parties have already agreed, by reason of the Varied Building Orders in the Building Order Review, that a grouting injection trial may proceed.
Despite agreeing to undertake a grouting trial in December 2023, the Applicant has not yet complied with the orders the subject of the Building Order Review.
The Respondent notes that, notwithstanding the detailed soil testing it has carried out; the Applicant's case is that it does not yet have 'a good understanding of soil conditions below the footpath' and therefore cannot meet the requirements of the arrangements agreed in the Building Order Review. Furthermore, the Applicant's position is that it cannot produce a scope of works due to the service providers' recommendation that the buried services in the area need to be accurately determined beforehand.
In response to these assertions, the Respondent submits that while service providers are to be notified of the works, the recommendations of these service providers should not preclude the Applicant from preparing a scope of works and eventually carrying out the required works.
Accordingly, the Respondent rejects the Applicant's explanation for not progressing with the agreed grouting trial. By failing to undertake the agreed works, the Applicant has, in effect, refused to implement what the Respondent regards as a viable alternative to demolishing the Building. Furthermore, the delay has resulted in the need for the Review to progress which would have been unnecessary had the Applicant complied with the Varied Building Order it agreed to in December 2023 in the Building Order Review.
In addition, the installation of hoarding around the Building would effectively mitigate any risk to the public.
Case overview: Applicant
The Applicant agrees that the phrase 'urgently necessary for … public safety', and the elements that comprise it, are not defined nor are they terms of art. Accordingly, the phrase ought to be interpreted by reference to the ordinary and natural meaning of its terms, read and understood together.
The ordinary and natural meaning of the word 'necessary' is not limited to 'indispensable' but also includes 'vital, essential, requisite'. In its context, the phrase 'urgently necessary for public safety' does not require that the works in question be the only way that a potential risk of injury or danger to the public can be mitigated or eliminated. Likewise, the definition of 'urgent' is not limited to requiring 'immediate' action.
The phrase 'urgently necessary for public safety' must be applied in its context, rather than the separate dictionary definition or meaning of each word, divorced from that context.[55]
[55] Harvis Capital Pty Ltd v Mid-West/Wheatbelt Joint Development Assessment Panel [2020] WASC 205 [77] - [78], [80] (Allanson J).
The Applicant agrees that item 18 provides for an exemption from the general position that works require development approval when works are 'urgently necessary for public safety'. However, it does not agree with the Respondent that the resolution of the question as to whether demolition of the Building is 'urgently necessary for public safety' turns on either of the two sub-issues identified by the Respondent (and set out at [126] above).
The Applicant emphasises that the Tribunal's task is to make the correct and preferable decision as at the time of the decision upon the Review. Accordingly, the Tribunal's findings in Sanur No 1, delivered in July 2021, are now of limited, if any, relevance.
The Applicant submits that there need not be an 'imminent risk' that the Building façade will collapse, in the sense that the collapse will occur within a very short timeframe in order to find that demolition is 'urgently necessary for public safety'.
The Applicant submits, based on the BG&E August 2023 Report, that a further rotation of 10.5 mm at the top of the parapet, or an additional settlement at the foundation of 4.2 mm, or a combination thereof, could trigger the collapse of the Building.
The temporary support structure was only designed to be in place for approximately six months and, in any event, would be ineffective as it will not prevent (or support) the collapse of the Building façade.
The Applicant submits that simply because the Building has not collapsed to date does not demonstrate that it will not do so in the future. It is not known precisely when further rotational movement and/or foundational settlement, sufficient to result in the collapse of the Building, will occur.
The Applicant does not agree that the Tribunal first needs to be satisfied that there is no other alternative to demolition of the Building that would ensure public safety, in order to find that the demolition of the Building is 'urgently necessary for public safety'. In any event, the Applicant's position is that there is no other alternative that will ensure public safety. That is so because no other option to stabilise the building foundation other than the grouting injection trial, has been proposed and furthermore, the grouting injection trial itself presents an unacceptable safety risk and is not a viable option.
The Applicant submits that the Respondent has not suggested any alternative proposal that will eliminate the risk of danger to the public from a potential building collapse. The Respondent's proposal for hoarding is not feasible, especially having regard to the adjacent footpath and Hay Street carriageway.
Issue 1: Whether the Building is in an active state of rotation
While the parties were not in agreement as to how item 18 ought to be read and applied, what is clear, on any view, is that for the exemption from the need to obtain development approval to be enlivened, demolition must be urgently necessary for public safety.
To determine that issue, we heard from four structural engineers, and a surveyor. Neither party sought to challenge the respective credentials, expertise or work experience of any of these experts. The one question from counsel that went to their relative experience related to their work on heritage buildings.[56] Mr Skinner, counsel for the Applicant, put to all the structural engineers that none of them had a lot of experience in dealing with heritage buildings.[57] In response, Mr Attilio Marra pointed out that he is the only structural engineer accredited, or recognised, as having heritage expertise in Western Australia.[58]
[56] ts 224, 232, 233, 29 October 2024.
[57] ts 283, 30 October 2024.
[58] ts 283, 30 October 2024.
Consistent with the cases put by the parties, as well as the overall tenor in which the evidence was given, in my view, each of these experts was suitably qualified and had the requisite depth and breadth of experience. However, in saying that, the engineering evidence was sharply divided.
On one hand, the Respondent's engineers (Dr Katz and Mr Marra) are of the view that demolition of the Building was not urgently necessary. On the other hand, the Applicant's engineers (Mr MacMillan and Mr Alasdair MacKerron) consider that, in effect, the Building is not safe, cannot be made safe and needs to be urgently demolished as a matter of public safety.
While four structural engineers gave evidence, only two of these engineers had undertaken their own assessments of the structural integrity of the Building. For the Respondent, Dr Katz, who has had the longest association with the Building, has prepared various reports stemming back from around February 2021. Dr Katz designed the temporary support structure that was installed and gave evidence, which was largely accepted by the Tribunal, in Sanur No 1. Mr Marra's evidence was more in the form of a desktop review, and interpretation, of the various engineering reports that have been prepared in relation to the Building.
For the Applicant, Mr MacMillan undertook investigations into the structural integrity of the Building. His calculations were then checked internally as well as by Mr MacKerron who, like Mr Marra, undertook a review of the various engineering reports and prepared his opinion thereon.
In some respects, the engineering evidence reduces to what might unhelpfully be labelled as a 'contest' between the evidence of Dr Katz and Mr MacMillan.
Respondent's engineering evidence
Dr Katz
Dr Katz has reported on the state of the Building on seven separate occasions following Sanur No 1.[59] Together with Mr Gaynor, he inspected the Building and viewed the tenancies from floor level. Dr Katz inspected the roof spaces of Tenancies 1, 2, 3, 6 and 7 via hatches or other openings and inspected the parapet from the roof.
[59] Exhibit 9, para 20, Exhibit 13 (Joint Report).
In June 2022, he explained that, as was his evidence in Sanur No 1, that the structural integrity of the Building was compromised.[60]
[60] Exhibit 3, page 69.
Dr Katz outlined that the most likely cause of the lean of the façade (and associated cracking) was due to the historical settlement of the foundational material below the dividing walls. The lean extends across the entire façade but is most acute towards the centre of the Building. Therefore, the lean is not the result of localised conditions, such as patches of loose sand, but is the result of a global effect across the façade.[61] He reiterated this view in August 2022.[62] The fact that the lean is most acute towards the middle of the Building is likely to explain why there is some evidence of some movement in Pier 7 (0.043 degrees over 23 months) sometime before Horizon Surveys commenced surveying the façade .
[61] Exhibit 3, page 74.
[62] Exhibit 2, page 704.
Dr Katz notes that there are high concentrated loads below each of the piers, where the weight of the façade bears downwards. In August 2022, it was his view that the centre of gravity of the façade wall above the supporting beam remained within the 'middle third' of the supporting pad at all locations, meaning it was stable. Where the centre of gravity shifts from the middle third, rotation is more likely.[63] However, even then, Dr Katz observed that if the centre of gravity should move outside of the middle third, this does not mean that the wall would overturn. He considered that a much larger lean and eccentricity would be required before overturing would occur.[64]
[63] ts 342, 30 October 2024; see also Exhibit 5, DM005.
[64] Exhibit 2, page 705.
At the final hearing, Dr Katz reiterated his view that the centre of gravity for the Building would need to shift a long way before the Building overturned. He explained that:[65]
So I took my computer model, which is - which started as a flat façade, and rotated it one degree or so, whatever the values were. 1.3 [degrees], worst case. I've also rotated it to two degrees, and - and it's not - it's not overturning. So, in my mind, it - it - it's not in an overturning mode.
That's not the - the key issue, and that's really - that's really why it's not explicitly stated because it's - it's just nowhere near - in a sense, that's an anecdotal or a qualitative statement. You know, I haven't tried to estimate what would it be involved to rotate it so far that it's now going to collapse. In other words, it's going to overturn. The centre of gravity is in front - is outside of the - of the support envelope … You know, we - we were talking about this other concept of the middle third, but the centre of gravity that needs to be outside of the base before the thing falls over.
In the case of the tissue box, it's - it's quite a steep angle. I also think it needs to be quite a steep angle for the facade. But I haven't needed to go there because it's just not currently a risk in my calculations. Clearly, Mr MacMillan has come up with a very different approach that has justified that that could happen.
[65] ts 415, 2 December 2024.
In 2022, Dr Katz undertook a preliminary calculation of the soil bearing pressure based on the information as it then stood. His initial (manual) calculation produced a maximum soil bearing pressure of 209kPa which he cross-checked with a simple computer finite element model (utilising specialist Space Gass software) which found the maximum soil bearing pressure to be 198kPa.[66] As these two values were within a range of 5%, Dr Katz was comfortable with his calculations.
[66] Exhibit 3, page 202.
However, Dr Katz later observed (in November 2022) two pier footings excavated from the Building's exterior and (in July 2023) the pier and wall footings from the interior (previously excavated by Galt). With more precise information on the nature of the footings, Dr Katz revised his soil bearing pressure calculations (again using Space Gass) based on the updated data. His revised calculations indicated a maximum soil bearing pressure of 225kPa (with no lean in the façade) and 258kPa (with a façade lean of 1.0 degree). Extracts from his finite modelling were included in his report.[67]
[67] Exhibit 3, page 205.
In the Joint Report of the Structural Engineers (Joint Report)[68] (discussed below), Dr Katz provided detailed commentary of piers 2 and 4. When he excluded any stabilising effects from the roof frame, the soil pressures at the front edge of the footings were as follows:
Pier 4 rotated, weight only: 157kPa
Pier 4 rotated, weight and earthquake: 210kPa
Pier 2 rotated, weight only: 224kPa
Pier 2 rotated, weight and earthquake: 284kPa
[68] Exhibit 13.
Dr Katz observed that if the stabilising force of the steel roof frames were included, the calculated soil pressure would reduce. The extent of that reduction will depend on the assumed load but will be no higher than the capacity of the two bolt to brick connections (40kN[69] estimated, included capacity reduction factors). Dr Katz calculations were as follows:
Pier 4 rotated, weight only, 12 kN resisting: 115kPa
Pier 4 rotated, weight, earthquake, 18 kN resisting: 132kPa
Pier 2 rotated, weight only, 12 kN resisting: 157kPa
Pier 2 rotated, weight, earthquake, 18kN resisting: 172kPa
[69] kN is a kilonewton, a unit of force in the International System of Units (SI) that equals 1,000 newtons. A 'newton' is a SI defined as the force required to accelerate a one-kilogram mass at a rate of one metre per second squared.
Dr Katz explains that the resisting load in the steel roof frames reduces the maximum soil bearing pressures. If higher resisting forces are used, the soil pressures below the footings can be reduced further and equalised. Dr Katz concluded that the high soil bearing pressures he and the other engineers have calculated (such as to exceed 200kPa) are unlikely to have materialised, which explains that despite the high calculated bearing pressures have not translated to any measurable vertical movements in the piers and façade in recent years.[70]
[70] Exhibit 13, page 12.
Dr Katz made detailed observations of the cracks that were present during his initial inspection and has monitored this over time. He records that between 17 February 2021 and 21 August 2023 (a period of 30 months) one new crack formed (at CR05 on Wall 3) approximately 6 metres back from the façade. Two other existing cracks widened by less than 1 mm.[71]
[71] Exhibit 3, page 312.
He has also compared two photographs of the cracking recorded in the Pritchard & Francis Report (in 1989) to photographs taken in 2022. Computer analysis of the cracks suggests that over the 33-year period, they widened by only 0.6 mm and 0.9 mm.[72]
[72] Exhibit 3, pages 313 - 314.
Having analysed the survey data, and consistent with the opinion expressed by Mr Bonus, which I will shortly come to, Dr Katz does not consider there has been active movement of the façade. For this reason, he does not accept the conclusion reached by ARUP that there was increased movement across the three tell-tales that were installed in February 2021. He says that this data is inconsistent with the overall presentation of the Building.
In fact, Dr Katz has long disputed the tell-tale results from the crack gauges. In his view, they were improperly installed and cannot easily, nor accurately, be monitored over time.[73] While the tell-tales suggest movement by as much as 12.5 mm since February 2021, Dr Katz was not provided with the original photographs or measurements of the tell-tales, only with the results. In his view, widening of the tell-tales in the manner described by ARUP (and BG&E) is inconsistent with the other concurrent data relating to the Building, namely the survey results which identify no recorded façade movement.
[73] Exhibit 3, page 6.
He also notes that while it may be that crack CR 10 (Wall 7) has moved by 5 mm, that too is consistent with the historic settlement of the foundation settlement discussed above. In relation to the other two telltales, Dr Katz observes that no damage was recorded on either the plaster on the other side of the wall, or, in the context of what ARUP suggests was a widening of 12.5 mm, in the plastered wall at either end of the exposed masonry where the tell-tale was installed. Furthermore, there is no cracking in the ceiling cornice above the tell-tale.
As I have explained, Dr Katz and Mr MacMillan attended a conferral in December 2022.[74] While Mr MacMillan was of the view that there was a 'risk of collapse or partial collapse', Dr Katz considered there to be 'no realistic risk' of that occurring. Both experts provided detailed reasons supporting their respective opinions.[75] Mr MacMillan pointed to the ongoing movement of the façade, as identified in the survey results since February 2021, in support of his conclusion.[76] Mr MacMillan also referred to the tell-tales installed in February 2021 as evincing movement in the Building.[77]
[74] Exhibit 3, item 2.
[75] Exhibit 3, pages 5 - 8.
[76] Exhibit 3, page 6.
[77] Exhibit 3, page 6.
In his most recent report, Dr Katz concluded:[78]
I have examined the available quantitative and qualitative evidence of façade movement, including survey data, tell-tale crack gauges, onsite assessment of crack widths, and comparison of a current and historic photographs. I concluded that the façade has not been in an active state of movement since current measurements on 23 January 2023. Prior to that, Pier 7 appeared to have rotated by 0.043 degrees over 23 months. Other than at Pier 7, the remaining façade has not been in an active state of movement since survey records commenced in February 2021.
[78] Exhibit 3, page 315.
Dr Katz remains of the view that the Building can be safely remediated; that the foundational material is currently stable and, moreover, can be strengthened by microfine grouting injections. He also proposes remediation works to the brick and timber superstructure such as connecting the façade to the roof structure, stitching across the cracks in the dividing walls, rebuilding small areas of masonry and providing a restraint to support the central pediment above the roof. He considers such works are feasible, straight forward and can be safely carried out.[79] His calculations confirm that the remedial works have sufficient capacity to maintain the required structural integrity.
[79] Exhibit 9, Annexure 3, page 3.
While Dr Katz notes that these remedial works will not reverse the façade rotation that has occurred, but it will resist further façade rotation and will reinstate the structural integrity of the Building. The degree of lean is not severe from a structural perspective and is not obvious to observers.
Dr Katz is also critical of BG&E's 'risk assessment'. In his view, the risk assessment has been carried out in a simplistic fashion, producing extreme and alarmist results. He considers that BG&E's inputs into its risk matrix are a misrepresentation of the process. As an example, Dr Katz takes issue with BG&E's assessment that the hazard 'façade collapse due to vertical settlement' was rated as '4' (meaning it 'could happen anytime'). Dr Katz does not consider that assessment to be of any real utility, because the hazard factors need to be much more specific and nuanced.
That is to say, the hazard or event must be not only that the façade must collapse but it must also collapse so as to be a threat to public safety. Dr Katz's point being that a façade collapsing is rare but the façade collapsing so as to hurt someone is even rarer. That fine grained, more nuanced, analysis has been omitted by BG&E. Accordingly, in his view, the risk matrix prepared by BG&E is too blunt; and produces extremely distorted, and alarmist, results.
Dr Katz notes that there has been no recorded movement of the Building façade since February 2021, and the City's geotechnical advice was that the significant foundation movement has likely already occurred. Together with the temporary support structure, Dr Katz considers that the appropriate risk rating for a partial collapse of the façade would be 'rare'. The resulting risk to life of a collapse would thus be even rarer. Dr Katz considers that there is no realistic risk to human life, at least at this time, from the Building collapsing.[80]
Mr Marra
[80] Exhibit 9, Annexure 3, page 4.
Mr Marra prepared a report on the structural integrity of the Building.[81] Mr Marra's view differs from that of Dr Katz. He considers that the Building façade is compromised, but current measurements do not indicate imminent collapse. This is evinced by the survey results.
[81] Exhibit 10.
Accordingly, like Dr Katz, he considers there is no imminent risk of failure. However, it is his view that remedial works to the Building need to be undertaken as soon as possible (in the form of soil stabilisation and repairs to the superstructure). Otherwise, the risk of failure remains. He also recommends the façade continue to be monitored going forward.
Applicant's engineering evidence
Mr MacMillan
Mr MacMillan is employed at BG&E. He first assessed the Building in September 2022. He has prepared three reports[82] (which he labels BG&E Report 1, BG&E Report 2 Rev A and BG&E Report 2 Rev B) and has participated in various expert conferrals.
[82] The BG&E Report 1 was prepared in September 2022; the BG&E Report 2 Rev A was prepared in July 2023 and the BG&E Report 2 Rev B in August 2023.
In his first report, his observations included that there was continued settlement below the load bearing piers. He described the façade as 'active, unstable and at risk of unpredictable collapse'. He also concluded that it was not viable to remediate the Building.[83] His view was that it was unsafe to undertake any geotechnical, inground or construction works due to the unpredictable nature of the soils and that access to the Building should be restricted.[84] His report included a risk matrix, which identified that the only mitigation option that was available was to demolish the façade.[85]
[83] Exhibit 2, page 753
[84] Exhibit 2, page 752.
[85] Exhibit 2, page 754.
He undertook a 'basic stability assessment'[86] and took account of the Pritchard & Francis Report, and the evidence of historical cracking. Mr MacMillan concluded that the remediation works recommended grout injections so as to prevent further movement of the façade. Given that the façade was, in his view, in an active state of rotation that, of itself, demonstrated that grout injections were an inadequate remediation option.[87]
[86] Exhibit 2, page 758.
[87] Exhibit 2, page 760.
To assess stability, Mr MacMillan utilised a statically determinate model[88] which assesses load paths through the structure down to the foundations. His model included an assessment of the façade stability, stability of the parapet wall, the bearing pressure on the soils together with the mass of the structure. His approach is set out further in the reasons of Sessional Member Pedersen. His ultimate conclusion was that the factor of safety (FoS) was below common industry standards.[89]
[88] ts 431, 432 and 454, 2 December 2024.
[89] Exhibit 13, page 10.
He references the three tell-tales that were installed in February 2021 and observed that while these recorded only small movements relative to the survey movements being recorded (up to 2 mm as at 26 March 2021[90] and 3 mm in July 2022),[91] he again concluded that it was evidence of the both the façade and the Building being in an active state of movement.
[90] Exhibit 2, page 762.
[91] Exhibit 2, page 771.
Mr MacMillan undertook a 'middle-third' calculation for four sections of the façade, the calculations for which included the movement being recorded by the surveys and the tell-tales. He concluded that the parapet panels at Tenancies 7, 5, 3 and 1 were deformed and are each reliant on rotational strain from the piers to remain stable and that the 'locked in' stresses cannot be relieved.[92]
[92] Exhibit 2, page 766.
Mr MacMillan then observed that movements in three of the panels exceeded those provided for in AS 1170: Structural design actions (AS 1170) which recommends allowable elastic deflections and deformity for masonry wall elements.[93] Mr MacMillan, again based on the survey results, concluded that the façade parapet was moving at particular reference points by up to 35 mm, 56 mm and 40 mm such that the recommended tolerances within AS 1170 were being exceeded.[94]
[93] Exhibit 2, page 767.
[94] Exhibit 2, page 768.
Mr MacMillan assessed the pier at Tenancies 3 and 4. He observed that the surveyed movements indicated that rotation is occurring. The unbalanced load was creating high bearing pressures at the front face of the pier foundation, which are likely to exceed 250kPa. The geotechnical advice from Galt indicates that there is no acceptable bearing pressure that can be applied to the sand foundation at shallow depth. He concluded that unpredictable (further) settlement is likely to occur.[95]
[95] Exhibit 2, page 768.
As part of the Review, Mr MacMillan attended a conferral with Dr Katz on 19 December 2022. During that conferral, Mr MacMillan set out, inter alia, detailed reasons why he considered that the Building façade could collapse imminently and was thus a risk to public safety. These reasons included:
(a)there was 'observed movement' in the Building as well as cracking;
(b)the soil beneath the façade foundation is very loose (poorly compacted);
(c)surveying of the façade indicates ongoing movement;
(d)the tell-tales indicate movement up to 12.5 mm;
(e)the centre of mass of the piers is, in places, outside of the middle third and are at risk of overturning; and
(f)the temporary building support will not prevent further rotation of the piers onto Hay Street.[96]
[96] Exhibit 3, pages 5 - 8.
Mr MacMillan subsequently undertook further investigations of the foundational soils and footing system below the façade of the Building in May and June 2023. Trial pits were dug to expose the as-built foundation systems and to enable the foundational soils to be assessed.[97]
[97] Exhibit 3, page 115.
From those further investigations, Mr MacMillan concluded inter alia that:
(a)there is no integrated foundation system below the Building;
(b)the basis upon which Keystone Structural had previously assessed the foundations is not valid as no concrete strip footings have been located; and
(c)the calculated bearing pressure on the measured pad footings below the pier footings exceed the ultimate bearing capacity of a loose sand foundation.
In August 2023, Mr MacMillan undertook further site investigations and calculated revised bearing pressures. Those revised calculations indicated bearing pressures exceeding 300kPa (338kPa and 326kPa) which is considered to be 'very high for the loose sands'. In undertaking those further investigations, additional cracking was observed at the junction of the load-bearing masonry pier and the underside of the steel beams supporting the parapet wall.[98]
[98] Exhibit 3, page 302.
In August 2024, Mr MacMillan prepared a submission as part of the JDAP Application outlining the state of the Building.[99] In that submission, Mr MacMillan reiterated that long-term movement of loose sands below the Building's foundations has caused vertical rotation of the façade. He further explained that the surveys evinced 'an ongoing downward movement trend' and that 'settlement is clearly happening, trending well into the tipping point, and that is not in question'.[100]
[99] Applicant's Bundle, pages 291 and 299.
[100] Applicant's Bundle, page 296.
Mr MacMillan also explained that bearing pressures on the sand exceed 300kPa (and the point at which Mr Marra considers that demolition is required). The FoS against over-turning was then assessed as low as 1.08, whereas it should be between 1.5 and 2.0. He further explained that remediation, by way of liquid grout injections, would not work given the highly stressed soils. In his view, any further settlement greater than 4 mm would cause the Building to collapse.
Mr MacMillan also took part in the structural engineers' conferral in October 2024.[101] In that conferral he explained, inter alia, that the surveys that were undertaken of the façade 'indicate ongoing vertical settlement of the façade'. Mr MacMillan reported cumulative settlements ranging from 7 mm to 13 mm. Mr MacMillan restated his overarching opinion that the façade is 'in an active state of movement'.[102]
[101] Exhibit 13.
[102] Exhibit 13, pages 5 and 6.
Mr MacMillan also estimated the soil bearing pressures to be between 352kPa (for the pier with the highest lean) and 523kPa (for the pier with the smallest footing).[103] He included additional sketches and supporting information in the Joint Report, including DM002/003 which identified trending vertical settlement for three survey points between February 2022 and July 2023.[104]
[103] Exhibit 13, pages 11 and 12, DM004/DM005.
[104] Exhibit 13, DM002/003.
In broad summary, Mr MacMillan's overall view remains that:
(a)the Building (including the façade) has a long history of reported cracking and building settlement conditions;
(b)the Building has moved well beyond the recommended structural limits (as defined by AS 1170);
(c)the soils at the site are assessed as loose extending to around 0.45 metres to 1.65 metres below the bases of the pier footings;
(d)differential settlement of the pier and cross-wall footings, due to the foundational material, is the key contributing factor to the observed movements of the Building;
(e)the Galt Geotechnical Report described the soil as unpredictable and with minimal external influence (vibration or introduction of water) may lead to uncontrolled settlements and an extreme risk of collapse;[105]
(f)the Horizon Surveys results show there is continued and ongoing settlement and Building movement;
(g)the existing façade is considered to be active, unstable and, due to the risk of unpredictable settlements, at risk of collapse;
(h)the propping that has been installed in the Building is ineffective and will not prevent or contain a collapse. There is a trend, which is ongoing, of outward and downward movements;[106]
(i)the masonry is brittle and there is no redundancy or alternative load paths available in the building structure; and
(j)the Building façade presents an extreme risk to safety.[107]
[105] Exhibit 2, page 784.
[106] Exhibit 11, para 26.
[107] Exhibit 11, para 25.
Mr MacMillan also considers that the behaviour of the Building cannot be predicted, including during any proposed remediation works. There would be a lack of warning ahead of any partial or full collapse. Examples of sudden failures include:
(a)Swanston Street wall collapse, Melbourne (2013);
(b)Old Royal Hotel, Melbourne (2016);
(c)Matilda Bay Brewery, Perth façade parapet collapse (2017); and
(d)Westralia Square, Perth pedestrian footbridge collapse (2019).
In the Joint Report, Mr MacMillan concluded that:[108]
The Building has moved well outside of the acceptable structural limits resulting in large cracks and defects in the building fabric. … The masonry is brittle in nature and there is no redundancy or alterative load paths available. The supporting soil is loose and highly stressed and there is an ongoing trend of vertical settlement. Given these observations, the behaviour of the building in its current state and during any proposed remediation works cannot be predicted. There would be a lack of warning of any partial or full collapse[.]
For the pier analysis, Dr Katz used a working load model that assumed a footing running right to the rear of the 1.5-metre-long dividing wall section. He calculated front edge bearing pressures to the low 200s kPa (224kPa revised to 258kPa when the footing dimension as measured during the BG&E site investigation is adopted), with a triangular distribution of pressure all the way to the rear of the wall, indicating the brickwork is all in compression for the existing rotation of the structure. This did not include the earthquake load. To engage the wall in the calculation he included continuity of load through the Pritchard Francis-designed steel wall ties but noted that this is subjective since it is unclear how much these ties are engaged. He found the pier model would be stable in overturning if the façade lean was changed from 1 degree to 2 degrees.
Dr Katz described his understanding of overturning stability; he identified that instability occurs when the overturning moment exceeds the restoring moment and the centre of gravity of the structure rotates over the leading edge of the footing.
Dr Katz identified that his model and calculations have not been checked or reviewed.
Dr Katz noted that the starting point is different in determining the performance of a heritage structure versus the design of a new build. In a new design the process is to calculate a design capacity to Australian Standards prior to construction. An existing building is already standing, and the loading capacity may not be clear, the strength and behaviour of old materials may be difficult to determine. It also may not be possible to return it to an as-new condition, but it may be able to be strengthened. He noted it is not common for a client to accept a reduced capacity. Deflections may be able to be characterised as a performance tolerance rather than as a construction tolerance, which is what is prescribed in Australian Standards. An increased deflection may therefore be acceptable; however he would not advocate lower safety factors on overturning.
Dr Katz identified that in this case it is necessary to improve the foundation. The footing may need to be widened or extended inside the property boundary.
Dr Katz identified that the Building does need urgent work. His calculations have demonstrated the Building could undergo further movement, and despite the Building being in the current condition for a long time, that does not mean that there will not be incremental or steep change. Dr Katz expressed the opinion that there will be more recorded movement before failure occurs, noting that sudden failure is possible.
Mr Marra
Mr Marra has a 30+ year career in structural engineering.[177] He is chartered across the Civil, Structural and Heritage/Conservation Colleges and has a depth of experience across all these areas including relevant heritage projects. Mr Marra has worked in a number of consulting engineering firms undertaking a range of structural engineering design tasks, including on major projects. He founded his own consulting business in 2009 and continues to undertake a range of projects. Mr Marra continues in a hands-on structural assessment and design role in his own firm and additionally has undertaken qualifications and professional development in aspects of safety in building practice. He demonstrated relevant awareness of remediation of buildings in Italy rendered unstable following an earthquake.
[177] Exhibit 10.
Mr Marra was engaged to do a high-level review of the previous engineering reports, and he did not do his own calculations nor check the calculations done by either Mr MacMillan or Dr Katz. The limited scope he was engaged to undertake perhaps took less advantage of his expertise than may have otherwise been helpful to the Tribunal.
Mr Marra noted that geotechnical considerations are beyond his areas of expertise, so has not assessed the geotechnical risks including those induced by grouting.
Consideration
All the structural engineers are suitably degree-qualified within what Engineers Australia would define as the occupational classification of Professional Engineer. Each holds-chartered status, indicating professional association recognition of their formative experience, their audited ongoing development and their commitment to a code of professional ethics.
The extent and depth of experience in structural engineering does vary significantly. Between the two primary engineering witnesses, I find that Mr MacMillan has a much greater extent, depth and breadth of structural engineering experience than Dr Katz, and this differential is clearly reflected in the evidence.
The evidence given by Mr MacMillan, other than his emphasis on survey trends, was clear, consistent and based on industry standard calculation and risk assessment methodologies that were checked and reviewed.
The evidence given by Dr Katz was inconsistent. His findings are based on an unnecessarily complex method of structural modelling that I find is inappropriate in this context, was not checked and did not identify its modelling assumptions which are critical to the results produced by a finite element model. Dr Katz found significant overstress is present and yet put forward the opinion that this is not a problem. He provided no alternate risk assessment.
Each party put forward reviewers with a high level of experience and expertise. Mr MacKerron was in full agreement with the approach taken by Mr MacMillan, providing verification of his evidence and adding additional points that supported Mr MacMillan's approach. Mr Marra was not provided with the scope to review Dr Katz's work in this level of detail, however Mr Marra raised a number of key points that did not support Dr Katz's approach, such as the lack of vertical support provided by the temporary frame.
Why I am satisfied that there is a risk of collapse that needs to be urgently addressed
Mr MacMillan put forward two clear mechanisms of potential catastrophic structural failure. He utilised industry-standard, straightforward statics-based modelling methods that are foundational to structural engineering methodologies, and his modelling of the structure is, in my view, transparent, easily checked, reliable and not conservative. He identified a determinate system, which is a structure where all forces can be calculated using equilibrium equations. He made rational and industry-standard assumptions about the load path, being the transfer of the gravity loads from building element masses directly downwards through the primary elements of the Building. He calculated that the loads under the parapet wall and footings are high and acting outside the middle third as a result of the weight of the structure alone. This is sufficient to demonstrate marginal or no safety factors are present against potential collapse. Environmental loads such as wind and earthquake add to the load offset and peak bearing pressure, but Mr MacMillan did not do further calculations to include these loads because his calculations already show the Building failing under its own self-weight alone.
Dr Katz used finite element analysis modelling of the structure which, in my view, is unnecessarily complex for a determinate system and carries a correspondingly high risk of error. The way the model is constructed can lead to very different results, for example Dr Katz found that the full length of the dividing wall is acting in compression to transmit load into the foundations. This is unlikely to be true in practice because the overwhelming bulk of the mass is in the parapet wall leaning forward over the pier, and the pier at the front. Dr Katz described how he varied the soil stiffness but saw minimal impact in the model output, which indicates that his model may not respond in a realistic way to vertical displacement of the foundation or distribution of loading. When asked specifically, Dr Katz did not identify the assumptions and boundary conditions inherent in his model. Moreover, his model and calculations were not checked by any other engineer. Checking (and for critical structures, independent review) are standard industry practices, and in this proceeding, it would have greatly assisted the Tribunal to have been presented with assurance of a comprehensive check and review of Dr Katz's model and calculations, particularly given the complexity of his modelling process and reliance on secondary load paths of indeterminate capacity.
The margins of safety calculated by Mr MacMillan for both failure mechanisms show there is very little remaining buffer against collapse. A FoS of 1 means there is no margin of safety, because at this value the forces promoting a collapse are equal to the capacity of the structure to withstand them. A FoS close to 1 indicates that the applied loading is at a point that is unacceptably close to building capacity. These marginal safety factors indicate that there is such a high potential for failure and wholly insufficient protection for public safety.
Dr Katz looked at load cases with environmental loading of wind and earthquake. As part of these load cases Dr Katz identified overstress associated with the identified failure mechanisms. In order to address the 20% to 75% overload that he calculated, Dr Katz made the assumption that environmental loading would pass into secondary load paths including the rear dividing walls, the roof frame, out of plane bending of the parapet wall and the temporary support frame. This relies on the load travelling through a more convoluted load path to reach the foundations. The condition, capacity and relative stiffness of the secondary members has also not been quantified, and this would be a necessary step to ensure that the secondary members can attract and carry the load. In addition, the out-of-plane bending of the parapet wall induces significant problematic tensile stress in the brickwork and it would go against industry practice to rely on this in any way as a restraining load path. To accommodate this, Dr Katz pointed to the lime mortar used in buildings of this era and noted they were typically more flexible than modern mortars.
The temporary frame does not appear to be acting as it was designed to, since the outer bearing pads are not all hard up against the parapet wall as indicated on the drawings. I concur with Mr MacMillan and Mr MacKerron that there is likely to have been load transfer from the parapet wall into the central bays of the temporary frame and that future removal of the frame may precipitate additional outward movement at the centre of the parapet wall.
I find that the temporary frame does not provide lateral restraint to the outer sections of the parapet wall and the piers, nor does it provide vertical restraint at any level. It is therefore not an effective aid in preventing or protecting against collapse initiated through vertical movement. It may be providing sufficient restraint to prevent the parapet wall moving outwards any further, thereby restraining further outward movement of the parapet wall mass, however I concur that removing the frame may transfer additional loading into the parapet wall which may cause the tensile capacity of the masonry to be exceeded.
I concur with Mr MacMillan and Mr MacKerron that there is ample industry precedent of brittle failure of structures. The examples provided in the evidence do demonstrate that catastrophic collapse of a structure may occur at any time without warning, even after the structure has appeared to be apparently stable for many years.
I concur with Mr MacKerron that the Building is not in a state where heritage considerations may moderate the structural assessment of the Building. The façade is significantly rotated from its original as-built condition, cracking patterns provide evidence of movement from the asconstructed configuration, the roof timbers are reportedly in poor condition, there is distortion visible in the leadlight windows, cracking where the steel beams land on the piers and a brick fell through the ceiling into a tenancy. None of this has been attributed to neglect of the Building, rather the bulk of the damage can be traced back to the past excavation of the services trench and resulting compromise of the foundations.
I concur with the Applicant's engineers that the façade cannot now be pushed back to the vertical and that there are now built-in stresses in the brickwork that were not present in the as-built structure. The builtin stresses contribute to an unquantifiable but real and significant chance of collapse.
I accept that the advice from Galt is that there is no acceptable value for an allowable bearing pressure under the footings. There is no way to determine whether the soil under the footings will continue to support the footing at the current level and distribution of loading and building lean. Nor can the likelihood of downward movement or rate of settlement of the soil under the footing be quantified.
I do not give credence to the statement by Local Geotechnics that further movement was 'unlikely' due to 'reasonably expected current and transient loading conditions, and with due consideration of existing structural restraint of the piers'.[178] It is not stated what information Local Geotechnics were given about loading conditions or the extent of restraint provided by the dividing walls, but this is a structural engineering consideration and not an opinion that should be entered into by a geotechnical engineer.
[178] Exhibit 13, pages 4 - 5.
I find that the foundation is highly vulnerable to excavation or soil voids adjacent to the footings, water ingress and ongoing soil consolidation, and that any one, or a combination, of these, occurring may precipitate building collapse. In addition, I find that the bearing pressures now present under the footings are higher than the geotechnical consultants have advised is allowable. The pressures have become less uniformly distributed and more concentrated on the footing leading edge, so consolidation of soil under the footings due to this load and load pattern is likely to lead to further concentration of load at an accelerated rate with a tendency for the footing to rotate outwards.
Mr MacMillan does appear to have placed great and possibly undue importance on small variations in the survey data. I find that the variations present in the survey data are not distinguishable from the station tolerance and this, combined with the small number of data points, means that any trend analysis will not be meaningful nor statistically valid. Mr MacMillan's attempt to identify a trend is perhaps understandable given the small additional movements that his calculations show may lead to progressive collapse. I find that it is unlikely that the ongoing survey monitoring is effective as an advanced warning of failure because the movement required to precipitate progressive collapse is so small and may well be indistinguishable from errors attributed to the survey tolerance.
I find that the demonstrated movement of the Building places it outside any leeway that could be provided to a longstanding structure due to undetermined material strength, secondary load paths or other unknown factors. The clear assessment of all four of the engineers is compromised safety factors. Because the failure mechanism is overturning, the strength of materials has very little bearing on whether the structure has sufficient strength. In addition, the pattern of bearing pressures of the footings onto the underlying sand has been demonstrably altered to the point there is a high load on the leading edge of the footing rather than the distributed load that would have existed before the rotation of the façade.
Overall, I consider there is a real and significant risk of collapse of the Building in its current condition. While the Building has been apparently stable, and possibly not moved significantly for many years, the risk of collapse has likely existed and possibly increased throughout the time since the building rotation was precipitated by the services trenching work in 1989. This indicates that urgent action is required to address the risk of collapse.
Why I believe demolition is the only available course of action
Both parties made submissions as to whether there are alternatives to demolition that could prevent building collapse and remediate the Building.
Dr Katz authored the list of measures that was included in the Respondent's Building Order to the Applicant. The sequence to facilitate injection grouting to stabilise the foundations was later expanded on in Tribunal proceedings by agreement between the parties. It is clear that Dr Katz has been a proponent of injection grouting but is 'all care, no responsibility' on this. He does not appear to have sufficient and relevant expertise or experience to determine whether this is a feasible option, and he confirmed in his oral evidence that this is the case.
On the other hand, Mr MacMillan does present as having the appropriate expertise and experience to specify whether injection grouting is a viable option. He has stated very clearly that it is not and provided a number of reasons including most fundamentally the potential for the injection of liquid grout to destabilise the soil under the foundations and cause loss of soil support for the heavily loaded pad footings, leading to building collapse. Other reasons include the lack of ability to determine whether the grout block has permeated the soil and extended under the footing, whether the grout block contacts the underside of the footing, the potential for the grout to ingress the services corridor and impact services and the inability to determine whether (or certify that) the actual required bearing capacity has been achieved.
My view is that Mr MacMillan's evidence strongly demonstrates that injection grouting is not an appropriate method of foundation stabilisation for the Building, and I conclude that trial grouting, whether at or remote from the pier footings, would yield inconclusive and uncertifiable results and in any case cannot be safely and reliably undertaken under the footings regardless of trial location or outcomes.
The remainder of the Building Order remediation items proposed by Dr Katz have been assessed by Mr MacMillan and I concur with his findings that many of these actions are not effective or safe to undertake. I find the Applicant was well justified in ceasing to affect the actions listed on the Building Order.
Mr MacMillan addressed a full range of remediation options in his risk assessment. Having reviewed the risk assessment and heard the evidence presented at the hearing, I conclude that the risk assessment has been carried out in accordance with industry standards and is comprehensive, including in the options it reviews which address several additional foundation stabilisation methodologies not identified by Dr Katz or Mr Marra.
Financial viability is rightly part of Mr MacMillan's method review process. Costs are commonly evaluated by engineers who carry this as a fundamental task of the practice of engineering. Engineers have a good understanding of the cost of undertaking works and as a matter of course contribute significantly or wholly to the development of estimates, tenders and bid evaluations. While the cost assessment is not the primary driver of the risk assessment per se, it would be unjust and overly onerous for the Respondent to require the Applicant to undertake a remediation measure that has been identified as cost prohibitive.
I concur with the outcomes of the risk assessment that demolition is the only option that mitigates the extreme risk identified.
Why I believe that failure constitutes a risk to public safety
The Respondent has proposed that access control measures, such as exclusion zones, should be considered to mitigate the risk to public safety. This requires the Tribunal to speculate about future actions that may be taken by the parties in relation to risk management, including possible road closures.
The Applicant has at various times in this proceeding advised they believe more extensive exclusion zones should apply in front of the Building, but it is the City who determines the extent of these and enacts them.
Accordingly, there is a demonstrated lack of communication and understanding about where the responsibility lies for risk mitigation for the Building. In my view, this ambiguity is a failing in the administrative control of risk that increases the risk to public safety by not clearly assigning responsibility.
In my view, the risk to public safety should be evaluated by considering whether normal access by the public places the public at risk.
The objectives expressed for non-residential developments in the City's Local Planning Policy 2.2 include:
…
(b)To encourage high quality, pedestrian friendly, street-oriented development that integrates with surrounding areas.
…
(e)To ensure that building frontages at the street level assist in the creation of safe built environments.
In my opinion, these local planning objectives provide a good indication of what 'normal' public access might encompass. Normal access to the Building and its surrounds is certainly not available to the public at this time. The City's aspirations for the amenity of this locality are unlikely to be available until the dispute over the Building is resolved.
In my opinion, the freedom of access in front of the Building provided at various times throughout this dispute has already placed the public at extreme risk. When questioned about the temporary support frame that he designed, Dr Katz did not provide the level of confidence about public safety that would be hoped, given that he knew pedestrian access was open under the frame.
In fact, during the final hearing Dr Katz noted that the temporary support frame would be unlikely to stop injury or death in the event of bricks falling from the façade and that it was not designed to do so. In my view, there appears to have been a significant disparity in understanding about the scope and function of the temporary support frame between the City and Dr Katz. Here again, responsibility is unclear, since the Respondent's engineer designed the support frame, and the Respondent issued a Building Order requiring the Applicant install it outside their boundary over the footpath. The City asked for a support frame to support the Building[179] and its intent may not have comprehended that the frame designed by Dr Katz was designed only to withstand a small percentage of lateral environmental loads.
[179] Exhibit 2, page 559.
At the time of the site view in October 2024, public access to the front of the Building could be obtained by hopping over some waist-high barricades with insufficient warning of the danger to the public and there was full access to all road lanes.
Should a catastrophic collapse occur, the exclusion zone for demolition which was previously designed by Structerre as the Respondent's engineer to close off lanes of traffic would be the minimum extent of exclusion required to protect the public, given that demolition is a controlled event and collapse is not.
The only evaluation of risk to public safety was put forward by Mr MacMillan and, in my view, his risk assessment provides a considered and well-documented process that codifies the risk. Dr Katz noted in the hearing that he may have categorised risk slightly differently, but there was no disagreement that significant risk to the public existed.
In my view, the level of risk documented by Mr MacMillan in table 2 of his report[180] to the risk assessment inputs detailed in tables 11 to 14 are a reliable and measured assessment of the level of risk to the public.[181]
[180] Exhibit 2, page 754.
[181] Exhibit 2, page 780.
The level of risk is therefore 'extreme'.
The risk mitigation actions and residual risks as documented by Mr MacMillan in table 2 of his report are, in my opinion, a reliable and measured assessment of the possibility and outcomes of risk mitigation.[182]
[182] Exhibit 2, page 754.
Therefore, in my view, the only viable option identified that mitigates the extreme risk to public safety is demolition.
Additional considerations
No evidence was presented to the Tribunal on where responsibility lies in terms of risk mitigation for the Building. Should the Building collapse and have a human toll or cause damage, I ask the parties to carefully consider who is liable in this situation?
The Applicant has been consistent in its assessment that there is a danger to public safety and that the Building should be demolished, in addition to their advocacy for the continuation of extensive access restrictions.
Similarly, in the case of grouting trials ordered by the City, there is no indication of who would be liable for any mishap. The Applicant, having been advised of the risks by their engineer, has refused to proceed with the trials and there the matter has stalled.
Item 18(a) of the Table in cl 61(1) addresses cases such as this one, where there is a credible and demonstrated risk to public safety. It deliberately bypasses development approval such that demolition can occur prior to any review of any proposed development for the site. Refusal of a demolition permit on these grounds is therefore a moot point - what should have been properly and thoroughly assessed by the Respondent in its consideration of this demolition application is therefore the urgent need to demolish for public safety.
There has been no evidence presented that the Respondent has given more than a cursory consideration to the evidence of ARUP, BG&E or indeed its own engineer Structerre. The Respondent has engaged Dr Katz through Quoin and then Keystone Structural, in line with its policy to engage its own engineering advice. However, the City does not appear to have sought to seriously analyse the chasm between the expertise and opinions of these professional engineers, even when this was strongly supported by the accompanying letter from the WAPC on 28 September 2022.[183] The review by Mr Marra was not commissioned until the work leading to the July 2024 Engineering Design Consultancy (EDC) report in the lead-up to this hearing, and even that report does not serve to bridge the gap.
[183] Exhibit 2, page 800.
In its minutes and public announcements, the City has referred to Dr Katz's advice as the 'latest engineering advice', as though it supersedes all previous engineering advice. In my view, this downplays this very serious matter and dismisses the significant work and weighty opinion submitted to it for its consideration. Such consideration should be done with due and proper process, appropriate acknowledgement and mitigation of bias and risk, be documented and communicated to the Applicant.
In my view, public safety is likely to be at greater risk if the Respondent continues to push for building works, injection grouting trials and additional propping, due to a false sense that these measures will be effective and facilitate safe public access.
If anything, the City's complacency and lack of due consideration of all the engineering advice has endangered public safety.
Orders
The Tribunal orders:
1.The decision under review is affirmed.
2.The application for review is dismissed.
I certify that the preceding paragraph(s) comprise the reasons for decision of the State Administrative Tribunal.
DR S WILLEY, SENIOR MEMBER
7 OCTOBER 2025
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