ARCHIBALD and INNES
[2024] WASAT 142
•16 DECEMBER 2024
JURISDICTION : STATE ADMINISTRATIVE TRIBUNAL
ACT: BUILDING SERVICES (COMPLAINT RESOLUTION AND ADMINISTRATION) ACT 2011 (WA)
CITATION: ARCHIBALD and INNES [2024] WASAT 142
MEMBER: MR M BENTER, MEMBER
MS H PEDERSEN, SESSIONAL MEMBER
HEARD: 14 AUGUST 2024
DELIVERED : 16 DECEMBER 2024
FILE NO/S: CC 1265 of 2023
BETWEEN: YVETTE ARCHIBALD
First Applicant
MICHAEL ADRIAN VAN RHYN
Second Applicant
AND
SCOTT INNES
Respondent
Catchwords:
Building service complaint - Retaining walls - Whether faulty or unsatisfactory work or otherwise not proper and proficient - Form of building remedy order
Legislation:
Building Services (Complaint Resolution and Administration) Act 2011 (WA), s 3, s 5(1), s 7(1), s 9(1), s 10(1), s 11(1)(d), s 36, s 38, s 38(1)
Home Building Contracts Act 1991 (WA), s 3
State Administrative Tribunal Act 2004 (WA), s 60(2)
State Administrative Tribunal Rules 2022 (WA), r 39B, r 39B(5), r 39C
Result:
Application allowed in part
Category: B
Representation:
Counsel:
| First Applicant | : | Mr W Vogt and Mr M Humphry |
| Second Applicant | : | Mr W Vogt and Mr M Humphry |
| Respondent | : | Mr DJ Morris |
Solicitors:
| First Applicant | : | Vogt Legal |
| Second Applicant | : | Vogt Legal |
| Respondent | : | Dan Morris Legal |
Case(s) referred to in decision(s):
Gemmill Homes Pty Ltd v Sanders [2018] WASC 179
Griffin and SSB Pty Ltd [2024] WASAT 137
Kos and DND Building Co Pty Ltd [2020] WASAT 95
Louden and Changeovers Pty Ltd (ABN 18 146 623 190) [2021] WASAT 164
Owners of Island Apartments Strata Plan 52597 and Pindan Pty Ltd [2018] WASAT 2
REASONS FOR DECISION OF THE TRIBUNAL:
Background
In this matter the applicants, Ms Yvette Archibald and Mr Michael Adrian Van Rhyn, seek that building remedy orders be made requiring the respondent, Mr Scott Innes, to remedy claimed defects in, and associated with, retaining walls built by the respondent on the applicants' property in Bullsbrook.
On 13 February 2023, the applicants lodged a complaint with the Building Commissioner in relation to the retaining wall works pursuant to the Building Services (Complaint Resolution and Administration) Act 2011 (WA) (the BSCRA Act) comprising four complaint items, set out in the list of complaint items referred by the Building Commission to the Tribunal as follows:
Item Number Location Description of Complaint Item 1 Wall section dividing the grassed and paved areas Wall crack continuing to widen damaging paving and fencing in the process. No bonding blocks used as required in engineering plans. 2 All retaining walls. Do not contain bonding blocks as required on engineering plans. Likely cause of cracks and movement. Movement directly impacting through pipes with pressurised water and storm water. 3 Wall containing copper and white PVC pipework. Wall continuing to rotate outwards and pulling apart pipework. 4 Pavement along retaining wall. 4m long hairline crack may be due to pressure/movement of wall.
The complaint was accepted by the Building Commissioner's delegate on 3 March 2023 and an investigation was undertaken by the relevant Complaints Officer. On 3 October 2023, all four complaint items were referred to the Tribunal.
Evidence at the final hearing
The following parties gave evidence at the hearing:
(a)the first applicant, Ms Archibald; and
(b)the respondent, Mr Innes.
Concurrent evidence was given by the following expert witnesses at the hearing:
(a)Mr Brett Waddell, a civil structural engineer retained by the applicants; and
(b)Mr Brendon Bartlett, a structural engineer retained by the respondent.
Given the very limited amount of documentary evidence lodged in the course of the proceedings, the Tribunal for convenience prepared a hearing book for the purposes of the final hearing, which was marked as Exhibit A, and which comprises:
(a)at pages 1 - 11, the application form lodged with the Tribunal by the Building Commissioner and attachments (original complaint lodged by the applicants with the Building Commissioner, list of complaint items referred to the Tribunal and final investigation report);
(b)at pages 12 – 58, respondent's book of documents lodged on 6 March 2024;
(c)at pages 59 - 68, applicants' book of documents lodged on 15 March 2024, the only document in which is the expert report of Mr Waddell dated 15 March 2024;
(d)at pages 69 - 107, expert report by Mr Bartlett.
(e)at pages 108 - 110, the joint expert statement signed by Mr Waddell and Mr Bartlett arising from the expert conferral before members of the Tribunal on 18 June 2024;
(f)at pages 111 - 128, orders made by the Tribunal during the proceedings; and
(g)at pages 129 - 147, witness statement of the first applicant dated 13 August 2024.
As addressed at the hearing, while there were documents that were, on the face of it, lodged as confidential documents for the purposes of mediation, the parties confirmed at the final hearing that they had no objection to those documents being included in the hearing book.
The following additional documents were marked as Exhibits during the final hearing:
(a)Exhibit B - drawing prepared by the respondent showing work site, embankment and house location;
(b)Exhibit C - Reed Engineers drawings, Sheets 1 of 3 and 2 of 3, in respect of proposed limestone retaining walls at the applicants' residence, dated July 2019; and
(c)Exhibit D - Site plan identifying leaning portions of the retaining walls.
As noted above, there is a dearth of documentary evidence in this matter. In terms of how the matter proceeded to final hearing with such limited evidence, the Tribunal's record of the matter demonstrates that:
(a)the application before the Tribunal was lodged by the Building Commissioner on 4 October 2023;
(b)since 25 January 2024, the applicants have been represented by their current legal representatives;
(c)at a directions hearing on 2 February 2024, the Tribunal ordered that the matter be listed for a mediation on 22 March 2022. The orders also required that the parties, by 8 March 2024, each lodge:
(i)a written statement, of no more than two pages, headed 'Confidential - for mediation only' setting out the issues which they wish to discuss at the mediation; and
(ii)a book of documents in accordance with the form attached to these orders, containing an index (table of contents) and all the documents on which they wish to rely to prove their case, including expert reports, photographs and quotations and other documents relevant to the costings of the complaint items to be determined by the Tribunal.
(d)the order requiring the lodgement by each party of their book of documents also included the following note:
NOTE: All documents to be relied on must be included in the book, even though they may have previously been given to the Building Commissioner, because none of those documents have been given to the Tribunal by the Building Commissioner.
(e)in accordance with the above orders, the books of documents required to be lodged by the parties were not limited to documents sought to be relied upon in the scheduled mediation, but were instead required to include all documents to be relied upon by each party to prove their respective case;
(f)on 6 March 2024 the respondent, while self-represented in the proceedings, lodged the bundle of documents that appears at Exhibit 1, pages 12 - 58. While the bundle includes at page 1 what appears to be a confidential mediation document, the bundle was not lodged as a confidential mediation document and the balance of the bundle comprises various documents relied upon by the respondent, including relevant documents from the Building & Energy investigation process;
(g)on 15 March 2024, the applicants lodged a book of documents. While lodged as a confidential mediation document, the only document included in this book is the report dated 15 March 2024 by Mr Waddell, the engineering expert retained by the applicants. As such, the book is not properly a confidential document and, indeed, the engineering report included in the book was otherwise relied upon by the applicants for the purposes of the proceedings;
(h)at or immediately following the mediation on 22 March 2024, the Tribunal members who convened the mediation ordered that the matter proceed to an expert conferral, with a further mediation to be listed following the expert conferral;
(i)on 12 April 2024, the Tribunal ordered that a conferral of experts take place before members of the Tribunal on 18 June 2024;
(j)on 30 May 2024, further orders were made in respect of the expert conferral to proceed on 18 June 2024, including for the filing by the respondent of any further expert reports, and also requiring the parties to provide their dates for a final hearing with the matter to be listed for final hearing after provision of those dates;
(k)on 10 June 2024, a further expert report by Mr Bartlett dated 22 April 2024 was filed by the respondent;
(l)on 20 June 2024, following the provision by the parties of their available dates, the matter was listed for final hearing on 14 August 2024, with the relevant orders also providing that each party is responsible for ensuring that each of the persons who they propose to call to give evidence are in attendance at the commencement of the final hearing;
(m)on 12 July 2024, the signed joint expert statement of Messrs Waddell and Bartlett, arising from the expert conferral on 18 June 2024, was lodged with the Tribunal;
(n)on 2 August 2024, the applicants' legal representatives lodged a letter with the Tribunal seeking that the 14 August 2024 hearing be vacated and re-listed to a date not before 15 September 2024. The basis for the request, as set out in the letter, is that the Tribunal had not made any orders permitting the parties to file a book of documents for the final hearing or to adduce lay witness evidence at the final hearing by way of lay witness statements. However, as set out in the chronology above:
(i)the Tribunal's orders of 2 February 2024 had required that each party lodge a book of all the documents on which they wish to rely to prove their case; and
(ii)the Tribunal's orders of 20 June 2024 listed the matter for final hearing and required that each party ensure the attendance of the witnesses they proposed to call at that hearing;
(o)noting that the vacation of the final hearing was strongly opposed by the respondent, the matter was listed for a directions hearing on 8 August 2024;
(p)while the Tribunal, for the reasons given at that directions hearing, considered that the final hearing should proceed as listed on 14 August 2024, it also gave leave to the applicants to file a witness statement by the first applicant, Ms Archibald, by 13 August 2024.
The Tribunal also notes that, early during the final hearing, counsel for the applicants stated, in effect, that the matter was for all intents and purposes ready for final hearing. In any event, the view of the Tribunal is that the parties had been given appropriate opportunity to lodge with the Tribunal all documents upon which they sought to rely in the proceedings and it is ultimately then a matter for each party as to what evidence they seek to proffer.
In accordance with the orders made at the close of the final hearing, the following written submissions were filed by the parties:
(a)applicants' written closing submissions dated 4 September 2024;
(b)applicants' written statement of orders sought dated 4 September 2024; and
(c)respondent's written closing submissions dated 18 September 2024.
Legislative framework and relevant principles
Pursuant to s 5(1) of the BSCRA Act, 'a person may make a complaint to the Building Commissioner about a regulated building service not being carried out in a proper and proficient manner or being faulty or unsatisfactory', with such a complaint being a 'building service complaint' pursuant to s 3 of that Act.
Relevantly, the definition of 'regulated building service' in s 3 of the BSCRA Act includes home building work that is carried out under a home building work contract.
In the Home Building Contracts Act 1991 (WA) (the HBC Act), 'home building work contract' is defined in s 3 to be 'a contract between a builder and an owner for the performance by the builder of home building work'. The definition otherwise excludes certain contracts, none of which exclusions are relevant or applicable to this matter.
Relevantly to this matter, s 3 of the HBC Act provides that 'home building work' means the whole or part of the work of:
(d)constructing or carrying out any associated work in connection with —
…
(ii)an existing dwelling, including a strata/community title dwelling;
In turn, s 3 of the HBC Act provides that 'associated work' includes, among other things, retaining walls, paving, landscaping and other like works.
Where a building service complaint is accepted by the Commissioner, the Commissioner must cause an investigation to be carried out by an authorised person and, upon considering the report of the authorised person, the Commissioner may, among other things, refer the complaint to the Tribunal to deal with: see s 7(1), s 9(1), s 10(1) and s 11(1)(d) of the BSCRA Act.
Where a building service complaint is referred to the Tribunal, s 38(1) of BSCRA Act provides that the Tribunal may:
…
(a)if the Tribunal is satisfied that the regulated building service that is the subject of the building service complaint has not been carried out in a proper and proficient manner or is faulty or unsatisfactory, deal with the building service complaint by making a building remedy order; or
(b)otherwise, decline to make a building remedy order.
Section 36 of the BSCRA Act provides relevantly:
(1)A building remedy order consists of one of the following —
(a)an order that a person who carried out a regulated building service remedy the building service as specified in the order;
(b)an order that a person who carried out a regulated building service pay to an aggrieved person such costs of remedying the building service as the Building Commissioner or State Administrative Tribunal, as the case requires, considers reasonable and specifies in the order;
(c)an order that a person who carried out a regulated building service pay to an aggrieved person a sum of money specified in the order to compensate the aggrieved person for the failure to carry out the building service in a proper and proficient manner or for faulty or unsatisfactory building work.
(2)A building remedy order may require that the order be complied with within a time specified in the order.
Consistent with previous decisions by the Tribunal,[1] the questions for determination in respect of a building service complaint are:
(1)Did the respondent carry out a regulated building service?
(2)If the answer to (1) is in the affirmative, was the building work, the subject of each of the complaint items, faulty or unsatisfactory?
(3)If the answer to (1) and (2) is in the affirmative, what is the appropriate form of the building remedy order (if any)?
[1] See in particular Louden and Changeovers Pty Ltd (ABN 18 146 623 190) [2021] WASAT 164 [5].
As to the discretion of the Tribunal to make a building remedy order under s 38 of the BSCRA Act, Smith AJ (as her Honour then was) stated in Gemmill Homes Pty Ltd v Sanders [2018] WASC 179 at [133] and [134]:
133It must be borne in mind that the statutory limits on the exercise of the discretion to make a building remedy order are only those set out in s 38. The repository of the power conferred to make an order (the Tribunal) must form an opinion that the regulated building service (that is the subject of the building service complaint) has not been carried out in a proper and proficient manner, or is faulty or unsatisfactory.
134If the requisite opinion is formed, the Tribunal is required to make a building remedy order. It then has to exercise the discretion conferred in s 36(1) to make a particular order in the form of s 36(1)(a), (b) or (c). Thus, no 'right' or requirement on a party to a complaint to elect arises.
In Owners of Island Apartments Strata Plan 52597 and Pindan Pty Ltd [2018] WASAT 2 (Pindan), the Tribunal set out at [27] to [35] the following principles relevant to determining whether work the subject of a building service complaint has not been carried out in a proper and proficient manner, or is faulty or unsatisfactory:[2]
[2] With the principles cited with approval by the Tribunal recently in Griffin and SSB Pty Ltd [2024] WASAT 137.
27The Tribunal has, pursuant to s 38 of the BSCRA Act power to make a building remedy order if it is satisfied that the regulated building service has not been carried out in a proper and proficient manner or is faulty or unsatisfactory.
28The standard of 'proper and proficient' is higher standard of care than 'proper and workmanlike manner' or the reasonable care and skill of a tradesman or contractor.
29The building contract may be relevant to the proper and proficient as it 'defines what the builder was required to do, which informs the issue of workmanship'.
30The phrase 'not been carried out in a proper and proficient manner or is faulty or unsatisfactory' is a broad expression apt to cover a wide range of deficiencies in the construction of a building which can be taken into account.
31Manufacturers recommendations may be departed from if the builder otherwise acted in a proper and proficient manner. A product which is performing well, and is suitable for its application, cannot automatically be said to be faulty or unsatisfactory.
32A mere departure by a builder from its contractual obligations is insufficient to establish the work was not carried out in a proper and proficient manner or was faulty or unsatisfactory.
33Builders are not compelled to search for and install superior products over and above what is adequate for the intended purpose.
34Where the issue is not contractual, the Tribunal should be cautious in regards to ordering remedial work to be undertaken unless the applicant has demonstrated a genuine adverse effect by reason of the building work in question.
35A building service that complies with the BCA will not be found by the Tribunal to be faulty or unsatisfactory or to not to have been carried out in a proper and proficient manner except in exceptional circumstances.
(Footnotes omitted)
The Contract and Works in issue
The four complaint items referred by the Building Commissioner to the Tribunal include a degree of overlap. Essentially, the complaint items all relate to works undertaken by the respondent, in respect of the retaining walls built at the applicants' home (the Works) that are alleged to be faulty or unsatisfactory, or otherwise not done in a proper and proficient manner. The specific complaint items comprise:
(a)cracking in the retaining wall section dividing the grassed and paved areas, with the wall crack continuing to widen and damaging paving and fencing in the process;
(b)the walls being constructed without bonding blocks as required in the engineering plans; and
(c)movement of the retaining walls causing damage to pipework in or attached to the walls.
As set out above, very little documentary evidence was filed by the parties in their books of documents. In particular, none of the following documents have been put into evidence in this proceeding:
(a)any quotation for the Works;
(b)any contract for the Works;
(c)any building licence or full set of approved plans for the Works; or
(d)any correspondence between the parties during the course of the Works.
While the witness statement of the first applicant refers to emails between the parties, written quotation documents and text messages sent by the applicants to the respondent, those documents are not in evidence before the Tribunal.
Notwithstanding the absence of relevant documentary evidence, there was no dispute at the final hearing that the respondent, through a trading name of the Limestone Wall Company, was the party that completed the Works. However, without there being any evidence before the Tribunal as to the terms of any contract between the parties, or any written specification for the Works, the Tribunal is unable to consider any contractual matters that may be relevant to the principles outlined in Pindan.
In her witness statement, Ms Archibald addressed:
(a)the discussions between the applicants and the respondent leading to the engagement of the respondent to undertake the works;
(b)the circumstances in which she was present at her home while the Works were being undertaken and the extent to which she observed the Works being progressed;
(c)her observations of the manner in which a different builder, not the respondent, constructed a small limestone retaining wall at some earlier time;
(d)that she did not see the respondent or his workers at any time lay any sand or undertake any compaction while building the first retaining wall that was part of the Works;
(e)her discussions with the respondent on site after seeing cracks appearing in the first retaining wall;
(f)matters involving the issue of building permits for the Works;
(g)discussions and correspondence with the respondent in relation to obtaining engineering plans for the second retaining wall being constructed as part of the Works;
(h)the extent to which she observed the respondent constructing the second retaining wall;
(i)that she did not see the respondent or his workers at any time during the construction of the retaining walls the subject of the Works install either interlocking blocks or anything that resembled Tensar grid or any other mesh products, nor did she see any such Tensar grid or mesh products being delivered to the property or otherwise on site at the property;
(j)her observations and discussions with the builder as to cracks appearing in the second retaining wall; and
(k)her observations as to further cracks appearing in the retaining walls or the increase in size of existing cracks.
At the hearing, Ms Archibald was cross-examined in relation to the evidence in her witness statement regarding the extent of her observations of the Works being undertaken by the respondent. This included Ms Archibald being shown the drawing marked as Exhibit B, which indicates a significant embankment on the site and limited visibility of the work site from the main house. Ms Archibald disagreed that Exhibit B accurately depicted the site and maintained her position that she had a clear view of the Works being undertaken and, while not watching for 100% of the time, was present and watching for a significant percentage of the Works.
The first applicant gave clear and concise evidence. However, to the extent she expressed views or concerns as to the manner in which the respondent undertook the works, the Tribunal gives limited weight to that evidence. Particularly in respect of her evidence as to observations of how an unrelated builder constructed a small retaining wall on the applicants' property at some earlier time, there is no context provided to suggest that this evidence supports any contention that the Works by the respondent was in some way faulty or unsatisfactory or otherwise not proper and proficient.
While evidence was given by the applicant regarding her observations of the Works being undertaken, no expert evidence was produced by any registered building inspector in relation to matters such as:
(a)the typical manner in which retaining walls such as those comprised in the Works would be undertaken by a builder; and/or
(b)whether the manner in which the respondent undertook the Works was, from the perspective of such a building inspector, considered to be faulty or unsatisfactory or otherwise not proper and proficient and, if so, the reasons for that view.
The respondent's evidence-in-chief at the hearing was to the following effect:
(a)the relevant structural drawings for the retaining walls to be built by the respondent at the applicants' residence are those appearing at Exhibit A, pages 101 - 103;
(b)those drawings are the design of Brian Reed, of Reed Engineers, who the respondent has used for 25 years and whose designs do not change;
(c)those drawing are what the respondent built the wall to and the respondent strictly follows the engineer's detail;
(d)there was no need for sand to be added prior to construction of the retaining walls, as the site is hard clay;
(e)rather than bonding blocks, the respondent used Tensar mesh to tie the front section of the wall to the back section in order to prevent delaminating;
(f)the Tensar comes in a 100-metre roll and sits on the back of the truck. The respondent's workers then cut the mesh to the required length, be it 1 metre or 700 millimetres, and install it as required;
(g)while the first applicant gave evidence that she never saw the mesh on site or being installed, the respondent's evidence is that it is definitely in the wall;
(h)with the wall in question, there was a very steep embankment, with a 3.3 metre difference between ground level and finished floor level. When the respondent's team were building the wall, the difference in height meant that it was not possible to see into the house. Rather, when standing up at the base of the wall, the respondent could see the roof line of the house, but not the house itself at all;
(i)because this was a clay site, it did not require compaction and no compaction was done;
(j)a three-tonne excavator was initially used to try to clear the site for the retaining walls however, because the ground was so hard, a ten-tonne excavator was instead required to dig the site to the required depth;
(k)if it was a sand site, which required compaction, the respondent has a vertical rammer on the back of the truck, which is used for compacting. The only time that was used on the applicants' site was for a small return wall, described as 'EX. RETAINING WALL' near Location 1 on the site plan at Exhibit A, page 73, which returned back on sand that the respondent did not bring to site and which he believes was part of the original sand pad for the house. But as the retaining walls included in the Works were on a clay base, no compaction was undertaken for those walls;
(l)when doing the Works, the respondent would generally see the first applicant in the morning but did not see her throughout the day. While she would sometimes come to the work area for a look around 2.30 pm, that was generally the only time the respondent would see her until the end of the day;
(m)when the Works started, the respondent was initially working on the basis of a different design for the wall;
(n)the respondent did not include bonding blocks, as shown on the design, and instead used the Tensar mesh;
(o)while the 'Limestone Retaining Wall Notes' on the Reed Engineers design[3] refers to compaction being required, no compaction was undertaken. This was because the relevant design was for a retaining wall undertaken as part of previous works on the applicants' site, but the walls being built as part of the Works were on extremely hard ground that did not require compaction;
[3] Exhibit A, page 102.
In cross-examination, the respondent's further evidence was to the following effect:
(a)when the Works commenced, the respondent was initially constructing the retaining walls working from a different design;
(b)bonding blocks were not used, with Tensar grid being used as an alternative;
(c)while the wall design drawing[4] notes refer to compaction, the respondent says that was the design for a different wall;
(d)upon then being shown Exhibit C,[5] including the note that "THESE WALLS ARE APPLICABLE TO SANDY SOILS ONLY", the respondent maintained that no compaction was required given it was a clay site;
(e)in using a ten-tonne excavator, the required dig is undertaken with precision, using a string set-up and having the excavator operator dig exactly as required, with the respondent also saying that his excavator dug the site perfectly in respect of the Works;
(f)the respondent considers the use of a ten-tonne excavator to be proper and proficient;
(g)the respondent considered that Tensar grid could be laid either continuously or in sections;
(h)while not visible in the photo of one of the partly constructed retaining walls,[6] the respondent maintained that, while not installed continuously, Tensar was installed in the wall in staggered sections;
(i)while not able to remember exactly how the Tensar was installed in these retaining walls, the respondent said that a section of Tensar could be installed every two to three metres and he believed that would do the same job as interlocking blocks when staggered in that manner;
(j)when Reed Engineers signed off on the retaining walls, they were taking the respondent's word that Tensar had been installed; and
(k)while the respondent accepts that the engineering drawings require bonding blocks, he maintains that Tensar is a substitute.
[4] Exhibit A, page 102.
[5] Being Reed Engineers drawings Sheets 1 of 3 and 2 of 3, in respect of proposed limestone retaining walls at the applicants' residence, dated July 2019.
[6] Exhibit A, page 31.
Expert Evidence
As noted above, expert reports by Mr Brett Waddell and Mr Brendon Bartlett were filed during the proceedings by the applicants and the respondent respectively.
Pursuant to orders made by the Tribunal, Messrs Waddell and Bartlett attended an expert conferral on 18 June 2024 convened by members of the Tribunal. The joint expert statement arising from that conferral was signed by Messrs Waddell and Bartlett on 2 July 2024 and lodged with the Tribunal by the applicants on 12 July 2024.
In relation to the conferral process, r 39B of the State Administrative Tribunal Rules 2004 (WA) (the SAT Rules) provides:
39B.Conference of experts pre-hearing
(1)This rule applies if in a proceeding the Tribunal orders experts with a common or overlapping expertise to confer and to file a joint statement about matters such as the points on which they agree and disagree.
(2)Unless the Tribunal orders otherwise, the experts must confer in the absence of the parties and the parties' representatives.
(3)An expert who is required to confer must not, before the joint statement is filed, discuss any matter raised in the conference with, or disclose any such matter to, any person who is not part of the conference.
(4)Evidence of anything said or done in the course of the conference of experts, other than the joint statement, is not admissible at any later stage of the proceeding without the Tribunal's leave.
(5)Unless the Tribunal orders otherwise, it will admit the joint statement filed by the experts into evidence at the hearing of the proceeding.
(6)If the joint statement is admitted into evidence, no party can adduce any evidence inconsistent with any matters on which the statement says the experts agree, without the Tribunal's leave.
At the start of the final hearing, the joint statement of Messrs Waddell and Bartlett was admitted into evidence by the Tribunal pursuant to r 39B(5) of the SAT Rules.
As set out in their joint expert statement, Messrs Waddell and Bartlett agree on the following matters:
(a)The geometry of the limestone blocks matches the design (based on photographs taken during construction and provided to review).
(b)The sub-soil drainage has been installed adequately.
(c)Isolation joints are sufficient and in accordance with the original design.
(d)The original engineered retaining wall detail did not specify a backslope.
(e)Some vertical movement is to be expected on a clay site. The inclusion of isolation joints is intended to accommodate this.
(f)It is unlikely to expect further significant movement of the wall.
(g)If bonding of the limestone blocks can be either confirmed or retrospectively installed, the wall will be structurally sound.
(h)Some method of isolation/expansion would be expected to be installed to the paving behind the wall (noting however that the experts also recorded that paving is not an area of expertise of the experts);
(i)Tensar/geogrid products can be used as an alternative to bonding of limestone backing blocks. The Tensar should be installed in a continuous manner.
(j)Bonding could be retro-fitted (dowelled and epoxied reinforcing) to comply with the original design.
The two matters in respect of which the experts do not agree, as set out in the joint expert statement, are:
(a)whether the extent of movement of the wall is more than expected; and
(b)whether partial re-construction of the wall at the point of maximum rotation should be carried out.
In relation to the extent of movement of the wall, Mr Bartlett's view, as recorded in the joint expert statement, is that the movement is not more than expected for the following reasons:
(a)The site has been previously classified as M class (2040 millimetres of expected vertical surface movement between wet-dry extremes).
(b)Calculations indicate that a ~15 millimetre vertical subsidence at the toe of the wall, corresponds with the 25 millimetre of forward movement measured at the top. This is considered to be within the expected movement of the clay site.
(c)There has been recent expended periods of high temperatures and low rainfall in the area. This has resulted in a higher-than-normal recent occurrence of shrinkage damage appearing in residences around the Perth area (where located on clay sites).
(d)All other potential causes for forward rotation of the retaining wall have been investigated and eliminated.
(e)The tolerance previously referred to (AS4678-2002, Table 6.1) is not applicable in this case, as this is a construction tolerance, not an intended performance tolerance. Furthermore, the horizontal position tolerance is 50 millimetres.
Mr Waddell's view, as recorded in the joint expert statement, is that the movement is more than expected for the following reasons:
(a)The wall has not been constructed in accordance with industry best practice, which is to construct the wall with a two (2) degree back lean. Which by default, provides some minor allowance for movement.
(b)The site is a reactive site, and some vertical movement of the wall would be expected, however this is not considered to be the reason for the walls rotation.
(c)The rotation of the wall (25 millimetre at the top) if left unattended is likely to be identified by a building inspector, with negative connotations.
(d)The tolerance as specified in AS4678 is a reasonable allowance. The rotation of the wall has exceeded the limits as identified.
As to whether partial reconstruction at the point of maximum rotation should be carried out, Mr Bartlett disagrees that should be undertaken for the following reasons recorded in the joint expert statement:
(a)Both experts agree the wall is structurally sound.
(b)The wall has been constructed in accordance with the original engineering detail, which did not specify a back-slope.
(c)Any reconstruction of the wall will be for aesthetic reasons only and will not have any effect on the ongoing performance of the wall.
(d)These works are considered to be disproportionate to the extent of damage observed. Removing the mortar and replacing with a flexible sealant at this location will sufficiently improve the aesthetic appearance of the wall in this location.
In contrast, Mr Waddell considered that partial reconstruction at the point of maximum rotation should be carried out for the following reasons recorded in the joint expert statement:
(a)The geometry of the wall is adequate based on photographs; however, works would be required for the wall to be considered as structurally adequate, considering the lack of interlocking blocks.
(b)As detailed above leaving the wall with a lean outside of the recommended limits means that any minor movement of the walls over the remaining 50 plus year design life would place the wall well outside of acceptable limits.
(c)Being that the wall was not constructed in accordance with common industry standards it seems reasonable that the leaning section of the wall should be locally reconstructed to ensure that the wall can perform adequately for the approximate further 50 plus years.
At the final hearing, Messrs Waddell and Bartlett gave concurrent evidence in the manner set out in r 39C of the SAT Rules.
The Tribunal was greatly assisted by the evidence of Messrs Waddell and Bartlett. Both were clear and logical witnesses with appropriate engineering expertise and experience who provided credible evidence for the consideration of the Tribunal. Where differences in opinion were present, both provided clear reasons for those differences.
At the hearing, both experts gave evidence consistent with their positions recorded in the joint expert statement, including as to those matters on which they disagreed and the reasons for that disagreement.
In relation to the absence of bonding blocks in the wall, both experts agreed that Tensar grid, or an equivalent product, could be used as an alternative to bonding blocks, but only if laid continuously. The evidence was to the effect that the use of Tensar grid other than in a continuous manner, such as by way of the strips of Tensar said by the respondent to have been installed every two to three metres, will not achieve the same inter-locking capacity that bonding blocks would achieve.
Where Tensar grid had not been installed continuously through the retaining wall, the experts agreed in their joint expert statement that bonding could be retro‑fitted, by way of dowelled and epoxied reinforcing, to comply with the original design. During the hearing, the experts also agreed that this method, referred to during the hearing as rod stitching, is an appropriate way of addressing the de-lamination risk. The evidence was to the effect that this remedy involves drilling and bonding bars into the wall, and both experts agreed this would be approximately served by using 1 metre long stainless steel bars that are drilled and grouted or epoxied at one metre centres along the course 3-4 mortar joint and the course 5-6 mortar joint.
During the hearing, the experts were not in a position to advise on the precise details of this solution. Their evidence was that this method would require an appropriate engineering design to be prepared, however that would be a relatively easy task for an engineer to complete at a modest cost.
In relation to any requirement for compaction, Mr Waddell gave evidence to the effect that he considered that, on a clay site, excavation should be undertaken to the appropriate level with a sand layer installed and compacted to ensure there is a stable platform to start from. While his evidence was that the use of a ten-tonne excavator was not industry practice, this was on the basis that he did not believe the excavator could dig to level with sufficient accuracy and that the base of the excavation would be disturbed and would therefore require overexcavation, backfill and compaction. It was otherwise unclear how this was said not to be industry practice, noting that no evidence was called from any building inspector or other person with direct experience of undertaking site excavation for the purpose of building work. Mr Bartlett gave evidence that soil testing in front of the wall confirmed the in-situ soil at the level of the base of the wall does appear hard and has sufficient bearing capacity for a wall of this nature.
In relation to the forward rotation movement of the retaining walls, the evidence is that forward rotation is only apparent in specific sections of the retaining walls.[7]
[7] See in particular the site drawing and table in the report of Mr Bartlett at Exhibit A, page 73 and also Exhibit D.
Mr Waddell gave evidence that a two degree backslope is good practice in the design of retaining walls because any wall rotation will bring the wall towards vertical from its constructed position. Mr Bartlett's evidence was that a backslope is not mandated under standards and is at the discretion of the design engineer.
Mr Waddell gave evidence that Table 6.1 in 'Australian Standard AS4678 Earth-retaining structures' provides tolerances for deviations on retaining walls and that after 18 months the movement of the wall is outside these tolerances. Mr Bartlett gave evidence that the table reference shows construction tolerances which would be expected when the wall is in its as‑constructed position. In this regard, the Tribunal notes that there is no evidence before it that the wall was not within these tolerances at the time of construction.
Mr Bartlett also gave evidence that the construction alignment tolerances are a measure of the flatness of the finished construction surface of the wall compared to the drawings, not a measure of wall rotation. Mr Bartlett noted that it is unrealistic to consider that an earth retaining structure will not have shifted in 18 months. Further, the evidence from Mr Waddell about the two degree backslope at construction acknowledges that rotational movement is expected to occur over time.
Both experts gave evidence to the effect that a retaining wall interacts with the soil behind, in front and below it. Soil will settle and compact over time and with changes such as temperature, water content and surcharge loading.
Mr Bartlett also provided evidence of the presence of a large tree close to the base of the wall that may impact the wall rotation seasonally. However, no recommendations have been made in regard to the tree.
Consideration - Building service complaint
By reason of the provisions of the BSCRA Act and the HBC Act set out above, the Tribunal finds that the Works constituted a 'regulated building service' for the purposes of the BSCRA Act on the basis that:
(a)the construction of the retaining walls constituted 'home building work', as it was 'associated work' being carried out in connection with an existing dwelling;
(b)the agreement between the applicants and the respondent for the carrying out of the Works thereby constituted a 'home building work contract'; and
(c)the carrying out of that work under a home building work contract constitutes a regulated building service.
With the first question of whether the respondent carried out a regulated building service being answered in the affirmative, the next question is whether the Works were faulty or unsatisfactory or otherwise not carried out in a proper and proficient manner.
Based upon the evidence before the Tribunal including, in particular, the matters upon which the experts agreed in both their joint expert statement and in their further evidence at the final hearing, the Tribunal finds that the retaining walls the subject of this proceeding were constructed:
(a)with a geometry of limestone blocks and with a vertical construction, with no backslope, in accordance with the design detail;
(b)with embedment of the blocks into the soil at the base of 400 millimetre, being more than the 250 millimetres specified as a minimum base embedment;
(c)with vertical isolation joints, in respect of which neither expert saw any issues with the spacing or construction of those isolation joints;
(d)on a clay site, with sub soil drainage installed as specified; and
(e)without bonding blocks, being blocks placed at intervals in the transverse orientation to tie the wall layers together, as specified in the design detail.
In relation to the walls being constructed without the required bonding blocks, the Tribunal is satisfied from the evidence and finds that the use of Tensar mesh, or equivalent product, may be used as an alternative to bonding blocks, but only where the mesh is laid continuously.
As set out above, much of the evidence given at the final hearing by the first applicant and the respondent focused upon whether Tensar mesh was installed in the retaining walls. The respondent's evidence was that, while he could not recall the exact details, he installed a section of Tensar every two to three metres. The Tribunal is not satisfied that the respondent's evidence as to whether and, if so, in what manner, Tensar was in fact utilised in the construction of the retaining walls is clear or credible. In any event, the clear effect of the respondent's evidence was that, even if Tensar was utilised, it was only included in sections throughout the wall and not continuously.
As clearly agreed by the experts, Tensar or equivalent is only a suitable substitute to bonding blocks where it is laid continuously. This was clearly not done by the respondent in the course of the Works and the Tribunal is satisfied and finds that the failure to do so is faulty or unsatisfactory work. The potential impact of the lack of bonding is delamination of the front layer of blocks over the design life of the wall.
On this point, the Tribunal notes that towards the close of the hearing and after the evidence was closed, the respondent through his counsel made a concession that he would agree to undertaking the rod stitching solution, namely the retro-fitting of bonding by way of dowelled and epoxied reinforcing, that the experts agreed could be undertaken so as to comply with the original design. This proposal was not able to be advanced in the final stage of the hearing and, in light of the applicants' written submissions, is contrary to the form of order they seek from the Tribunal.
Other than the failure by the respondent to instal bonding blocks as required by the engineering design, or to satisfactorily instal Tensar mesh or equivalent product in a continuous manner as an acceptable alternative to the bonding blocks, the Tribunal is not satisfied from the evidence before it that the applicants have established that the Works are otherwise faulty or unsatisfactory or done other than in a proper and proficient manner.
While there is evidence of some forward rotation in some locations of the retaining walls, the Tribunal is not satisfied from the evidence before it that this constitutes faulty or unsatisfactory work or that the Works are not otherwise proper and proficient.
The primary argument by the applicants is that the forward rotation is a result of failure to compact the site and failure to construct the retaining walls with a backslope.
The clear evidence of the respondent was that, in respect of the retaining walls constructed as part of the Works, no compaction of soil was undertaken. Mr Waddell's evidence was to the effect that a layer of sand fill should have been compacted under the wall because an excavator could not excavate to level. In contrast, the respondent's evidence was that no compaction was necessary because the excavator was used to dig accurately to the required level guided by stringlines and the existing ground was hard. The respondent gave evidence that a threetonne excavator could not dig the soil and therefore a ten-tonne excavator was substituted. The respondent was credible in this claim that an experienced excavator operator can dig to level, particularly in a hard substrate, and that the substitution for a larger machine indicates the ground presented resistance to excavation. The respondent further noted that no sand foundation was specified so none was installed.
Based upon the evidence before it, the Tribunal is not satisfied that the applicants have established:
(a)that compaction was required to be undertaken by the respondent in the course of undertaking the works; or
(b)that, by not undertaking compaction, the respondent's work is faulty or unsatisfactory or otherwise not proper and proficient; or
(c)the respondent's manner of excavating and preparing the site was faulty or unsatisfactory or otherwise not proper and proficient.
Mr Waddell's evidence is that he would include a two-degree backslope, on the basis that some movement of a retaining wall is to be expected by reason of the mass of the material being retained. Mr Waddell also considered that it would be best practice:
(a)to design retaining walls with a two-degree backslope; and
(b)for a builder constructing a retaining wall to include a two-degree backslope, even where no backslope is included in the design.
Mr Bartlett's evidence was that it is a matter for the relevant engineer as to whether a wall is designed with or without a backslope and that the builder should construct the wall in accordance with the engineer's design.
As noted above, both experts agreed that the construction of the retaining walls with no backslope was consistent with the design.
On this issue, the Tribunal notes that there was no evidence adduced by either party from a registered builder or other party with appropriate experience of constructing retaining walls such as those the subject of the Works.
While Mr Waddell, in the joint expert statement, speculated that the forward rotation of the wall 'if left unattended is likely to be identified by a building inspector, with negative connotations',[8] no evidence in this regard was called from any building inspector retained by the applicants.
[8] Exhibit A, page 110.
Both experts also gave evidence to the effect that retaining walls are not well covered by Australian Standards. This means that engineering judgement is employed rather than there being a more formulaic or mandated approach. Standards such as AS3700 Masonry structures may be referenced for comparison but are not directly applicable.
The Tribunal is not satisfied that the applicants have established that there was any requirement for the retaining walls to be constructed by the Respondent with a backslope, particularly where the design did not include such a requirement.
The evidence before the Tribunal is that the forward rotation in the retaining walls is evident in a limited number of locations in the retaining walls. While reference was made at various times throughout the hearing of the largest amount of forward rotation being 25 millimetres, this is measured over the height of the wall in that location, being 2.6 metres high. In his expert report, Mr Bartlett calculates this to represent a forward rotation, over the height of the wall, of 0.55 degrees. In assessing the status of the wall at various locations, Mr Bartlett also observed that, in the majority of the locations, the wall is vertical or has a backslope.[9]
[9] Exhibit A, page 73.
As acknowledged by the experts, some movement of a retaining wall is expected and normal. The Tribunal finds that the wall geometry of the retaining walls is constructed as specified. As agreed by the expert witnesses, no issue of concern is raised in respect of the isolation joints and sub surface drainage.
Some movement of the wall is to be expected due to the soil-wall interaction. While an outward gradient may not be ideal, no backslope was specified in this case and the Tribunal does not consider that the wall moving to an out of vertical state, to the degree identified in this matter, constitutes faulty or unsatisfactory work by the respondent, or work that is otherwise not proper and proficient.
However, the potential for delamination of the front blocks over time remains an inherent fault with the wall that arises as a direct result of the lack of bonding blocks or equivalent alternative. This lack of protection against delamination is faulty and unsatisfactory. The applicant is entitled to have retaining walls with sufficient bonding throughout their design life to resist delamination.
Remedial works required to be undertaken
As noted above, the respondent made a concession towards the close of the final hearing, through his Counsel, to the effect that he would agree to undertaking the rod stitching solution, namely the retro-fitting of bonding by way of dowelled and epoxied reinforcing.
Without specifying the precise form of order that this would entail, the respondent's written submissions are to the effect that the only order that ought to be made is one to implement the 'Stitching Solution'.[10]
[10] As defined at paragraph 2(g) of the respondent's written submissions dated 18 September 2024.
This contrasts with the applicants' position set out in their written statement of orders sought that:[11]
As to the entire retaining wall system, the Applicants seek that the Tribunal makes a general remedy order as follows.
To remedy the complaints referred to in complaint items no. 1, 2, 3, and 4, the Respondent is to remedy the cause and effect of the defective retaining walls.
[11] Order 1 of the applicants' written statement of orders sought dated 4 September 2024.
In their submissions, the applicants rely upon the decision of the Tribunal in Kos and DND Building Co Pty Ltd [2020] WASAT 95 (Kos). However, the statements that the applicants attribute to the Tribunal in that decision have not been accurately reproduced in the applicants' written submissions. Rather, what the Tribunal stated in Kos at [67] was:
67It follows that the Tribunal may specify the work to be done in an order made under s 36(1)(a) of the Act where there are clear and unambiguous findings by the Tribunal about the method or approach that should be implemented to remedy the defects.
This Tribunal agrees with the observations in Kos regarding the risks of making specific building remedy orders. However, it also observes that, for the reasons set out in the decision, the Tribunal in Kos was nonetheless satisfied that a number of specific building remedy orders ought to be made.
In this matter, the Tribunal has made a clear and unambiguous finding that the failure by the respondent to install bonding blocks as required by the design, or to install continuous Tensar mesh or equivalent product as an alternative, is faulty and unsatisfactory. This is the only defect that has been established to the satisfaction of the Tribunal.
In relation to that established defect, the question is then what form of building remedy order should be made.
In this regard, the Tribunal is satisfied from the evidence before it that there is a single appropriate method of rectification that both expert witnesses have identified and agreed.
As noted above, the matters of agreement recorded in the joint statement signed by the experts included that:
(a)If bonding of the limestone blocks can be either confirmed or retrospectively installed, the wall will be structurally sound; and
(b)Bonding could be retro-fitted (dowelled and epoxied reinforcing) to comply with the original design.
While the evidence of the experts at the hearing acknowledged there would need to be some consideration of the precise materials, lengths and locations for the dowelled and epoxied reinforcing, they agreed that it would be a relatively straightforward task for an engineer to prepare an appropriate design.
Accordingly, the Tribunal considers it appropriate for a building remedy order to be made requiring the respondent to retro-fit bonding to the retaining walls the subject of the Works, by way of the installation of dowelled and epoxied reinforcing rods, with the design, material specification, oversight and verification of the bonding to be undertaken by an appropriately qualified and experienced structural engineer, the retention and payment for which will be the responsibility of the respondent.
The Tribunal will also order that the respondent address the major crack locations in the retaining walls by removing loose mortar, cleaning out the cracks to a clean finish and using a flexible sealant to fill the gaps. The Tribunal is satisfied that this is an appropriate order by reason of:
(a)the lack of required bonding in the retaining walls to date;
(b)the nature of the works that will be required to be undertaken to retro-fit bonding; and
(c)the position of Mr Bartlett in his report[12] and the joint expert statement[13] in relation to the removal of material in cracking locations and the replacement with flexible sealant.
[12] Exhibit A, page 82.
[13] Exhibit A, page 110.
However, while this work is considered appropriate to be undertaken by the respondent at this time in the course of undertaking the remedial work in respect of the defect established by the applicants, the Tribunal observes that inspection and replacement of flexible sealant when required is more typically an ongoing maintenance issue that falls to the homeowner.
As the Tribunal is not satisfied that the evidence before it establishes any other defect in respect of the Works, it is not necessary to consider the specific building remedy order sought by the applicants in respect of partial removal and re-construction of wall sections.
In their closing submissions, the applicants submit that they should have liberty to apply for costs and, in effect, propose timetabling for that to occur.
In light of all of the matters set out above, and particularly the specific findings made by the Tribunal, it is a matter for both parties to consider whether there is a basis for any costs application to be made. This may also turn to a degree on matters to which the Tribunal is presently not privy.
In the circumstances, the Tribunal will order that any party seeking costs may make an application by filing written submissions within 35 days (noting the intervening holiday period) and for the other party, or parties, to file any submissions in response within a further 14 days.
Accordingly, the Tribunal makes the following orders:
Orders
The Tribunal orders:
1.Pursuant to s 36(1)(a) and s 38 of the Building Services (Complaint Resolution and Administration) Act 2011 (WA), the respondent is to complete the following works by no later than 17 March 2025:
(a)the respondent is to retro-fit bonding to the retaining walls the subject of the proceedings, by way of the installation of dowelled and epoxied reinforcing rods, with the design, material specification, oversight and verification of the bonding installation to be undertaken by a structural engineer; and
(b)the respondent is to remedy the major crack locations in the retaining walls the subject of the proceedings by removing loose mortar, cleaning out the cracks to a clean finish and using a flexible sealant to fill the gaps.
2.The respondent is to carry out the remedial work the subject of Order 1 in a proper and proficient manner and make good any damage caused by the carrying out of the remedial work.
3.Any party seeking an order for costs to be paid by the other party is to file with the Tribunal and give to the other party, by no later than 20 January 2025, written submissions setting out the basis for any costs order and the quantum of costs being claimed.
4.Any written submissions opposing any costs order sought by a party pursuant to Order 3 are to be filed by the relevant party and given to the other party by no later than 3 February 2025.
5.Unless otherwise determined by the Tribunal, any application for costs shall be determined by the Tribunal on the papers pursuant to s 60(2) of the State Administrative Tribunal Act 2004 (WA).
I certify that the preceding paragraph(s) comprise the reasons for decision of the State Administrative Tribunal.
MR M Benter, MEMBER
16 DECEMBER 2024
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