Gedoun Constructions Pty Ltd v Agius - [2022] QCAT 446

QUEENSLAND CIVIL AND
ADMINISTRATIVE TRIBUNAL

CITATION:

Gedoun Constructions Pty Ltd v Agius [2022] QCAT 446

PARTIES: GEDOUN CONSTRUCTIONS PTY LTD

(applicant)

v

MARK ELLIOT AGIUS

(respondent)

APPLICATION NO:

BDL308-18

MATTER TYPE:

Building matters

DELIVERED ON:

14 February 2022

HEARING DATES:

24 August 2020
25 August 2020
26 August 2020
27 August 2020
8 September 2020
15 September 2020
27 January 2021
28 January 2021
12 April 2021
13 April 2021
14 April 2021
15 April 2021
16 April 2021

19 November 2021

HEARD AT:

Brisbane

DECISION OF:

Member McVeigh

ORDERS:

1.       The applicant must pay the respondent:

(a)    damages of $190,140;

(b)   liquidated damages of $32,050; and

(c)    interest at the rate of 10% from the date of this decision until the date of payment.

2.       Any application for costs must be made by filing in the tribunal two (2) copies and providing one (1) copy to the other party of any submissions and evidence to be relied upon within 14 days of the date of this decision.

3.       If any application for costs is made, then the other party must file in the tribunal two (2) copies and provide one (1) copy to the applying party of any submissions and evidence in response to be relied upon within 28 days of the date of this decision.

4.       The application for costs will be determined on the papers and without an oral hearing.

CATCHWORDS:

CONTRACTS – BUILDING ENGINEERING AND RELATED CONTRACTS – THE CONTRACT

GENERALLY – whether Australian Standard 4055 can be used to give a wind classification to a house if the prescribed geometric limits had been exceeded – whether Australian Standard 1684.3 can be used to derive a general wind classification to design both cladding and timber frame

Bellgrove v Eldridge (1954) 90 CLR 613 followed

McGrath Corporation Pty Ltd v Global Construction Management (Qld) Pty Ltd [2011] QSC 178 applied

APPEARANCES & REPRESENTATION:

Applicant:

Mr L Campbell with Ms B Vass instructed by Connolly Suthers Lawyers

Respondent:

Mr N M Cooke instructed by Becker Watt Lawyers

REASONS FOR DECISION

Background to the hearing

In 2013 a developer subdivided land in Mt Louisa, a suburb of Townsville. The developer prepared concept plans for houses in the subdivision and made them available to prospective purchasers of the subdivided blocks.
In 2017 Mark Agius (owner) bought a block of land in that subdivision. The concept plans for the block, which had been provided by the developer, were the basis of negotiations of a building contract between the owner and Gedoun Constructions Pty Ltd (builder).
On 4 October 2017 the owner and the builder signed a residential building contract. Under the contract the builder was responsible to provide the final design, to obtain council approval to build, and then to construct the house in accordance with the design.
In January 2018 the design was approved and construction commenced.
In August 2018 the builder claimed that the work was practically complete. Disputes regarding the quality of the work came to a head. The builder claimed its final progress payment. The owner refused to pay because of numerous alleged defects in the work. The owner complained to the Queensland Building and Construction Commission (QBCC). The QBCC issued a direction to rectify some of the defects and the builder undertook some rectification.
Meanwhile, the owner engaged Mr Hutton, a structural engineer and principal of FortisEM, to undertake a design review. Mr Hutton recommended that the owner obtain a specialist report regarding the classification and design wind speeds for the site. Based on the opinions of Mr Hutton and WindTech, the wind specialist, the owner formed the view that the house had not been designed, or built, to withstand wind loads to which it might be subject. In layperson’s terms – the owner thought that the house had been designed to a C2 wind classification when it should have been designed to a C3 wind classification. There is a significant difference between a house built to withstand wind speeds covered by a C2 rating and a house built to withstand wind speeds covered by a C3 rating. This difference lies at the heart of these proceedings.
In November 2018 the builder filed its claim for payment of the outstanding final invoice for $60,000, interest and indemnity costs under the contract.
Shortly after the builder’s claim was filed the owner paid the builder $46,256.82, having deducted $6,643.18 for negative variations and $7,100 for liquidated damages.
In March 2019 the owner’s counterclaim was filed. The owner:
(a)defended on the basis of set-off of his counterclaim; and
(b)counterclaimed for liquidated damages and damages for breach of the statutory warranties.
In its reply filed in April 2019 the builder admitted the claim for negative variations and denied that the owner was entitled to liquidated damages, alleging that the part of its claim remaining unpaid was $7,100 (including GST) and interest and costs under the building contract. As to the allegations regarding breach of the statutory warranties, the builder:
(a)did not respond due to lack of particularity; and
(b)noted that it remained committed to rectify legitimate defects.
The dispute was managed through the usual procedures of this tribunal. Unfortunately, each party became more entrenched in its position over time.

The hearing

The hearing commenced on 24 August 2020. As the quantum of the owner’s claim far exceeded the builder’s claim, the parties agreed that the owner’s claim be addressed first.
On the third day of the hearing, in response to the builder’s objection to the expertise of the person the owner intended to call to give evidence about the wind classification of the site, the owner sought and was granted leave to file a report from an alternative expert.
In order not to waste allocated hearing time, the hearing continued to deal with evidence going to issues other than wind classification.
In January 2021, following a conclave of the wind experts and the production of a joint report, I heard concurrent evidence from the wind experts. This was a very useful process, first because the joint report significantly narrowed the issues in dispute between the experts and second as it assisted me to understand the reasons for the remaining differences between the experts regarding the complex technical issues of wind loads, site classification and design wind speed for the site.
The evidence concluded in the week commencing 12 April 2021.
Written submissions were provided. Unfortunately, there was considerable delay in the production of the written submissions, caused first by the owner and then by the builder. The owner’s submissions and supporting spreadsheet was provided on 4 August 2021. The builder’s submissions on liability were provided on 15 November 2021 and on quantum with a supporting spreadsheet on 18 November 2021. I heard oral submissions on 19 November 2021. The owner’s written submissions in reply were provided on 26 November 2021.

Witnesses of fact

Agius

Mr Agius’ evidence in chief is contained in statements made on 13 December 2019[1] and 16 July 2020.[2] The documents referred to in Exhibit 1 are Exhibit 15 and the documents referred to in Exhibit 2 are Exhibit 16. He was cross-examined on 24 August 2020.
[1]Exhibit 1.
[2]Exhibit 2.
It must have been obvious to the builder, and it is hardly surprising, that Mr Agius had a keen interest in both the design and construction of his home. He spent four months discussing details of the design and specifications.[3] As issues emerged on site, e.g. geotechnical issues, he expressed his concerns.
[3]Exhibit 1, [51].
Mr Agius kept good records.
Mr Agius does not have qualifications in residential construction. However, it is plain that after construction of his home, he has gained considerable knowledge about such matters from various industry experts. However, his evidence about technical matters is not expert evidence and in many instances is hearsay.
As is the case with any witness, no doubt in the years that have passed since the events in question occurred, Mr Agius has placed emphasis on some memories which advance his case and forgotten things that were of no significance to him at the time.

Gedoun

Mr Gedoun is a director of the builder. His evidence in chief is contained in statements made on 10 June 2019,[4] 9 July 2020[5] and 19 October 2020.[6] He was cross-examined on 12 April 2021.
[4]Exhibit 42.
[5]Exhibit 43.
[6]Exhibit 44.
He holds QBCC licence number 76784.[7] The builder holds QBCC licence number 23628.[8]
[7]Exhibit 42, JG-1.
[8]Exhibit 42, JG-2.
Mr Gedoun has worked in the construction industry for over 27 years. He supervised design and construction through his staff.
For Mr Gedoun there was nothing remarkable about the contract for, or construction of, this house. He followed his usual business practices relying on appropriately qualified professionals for design input. There was a suggestion that he deliberately chose to construct this house to a C2 wind classification for the builder’s financial gain, however there is no logical reason for him to have downgraded the specification as the contract price reflected the house as designed; had the house been designed to a C3 wind classification, the contract price would have been higher.
I reject the owner’s submissions that I should not accept Mr Gedoun’s evidence on defects because it is self-serving. The tribunal is not bound by the rules of evidence.[9] My approach is to consider his statements, his cross-examination and contemporaneous documents and then to attribute appropriate weight to the material in making my findings.

Expert witnesses

[9]Queensland Civil and Administrative Tribunal Act 2009, section 28(3).

Boughton

The owner relied on expert evidence from Dr Boughton, an adjunct associate professor and senior research engineer at the cyclone testing station at James Cook University. His PhD, awarded in 1989, was on performance of full-scale timber-framed houses in cyclonic winds. His career focus is on performance of buildings during tropical cyclones and providing technical and research support to the timber and building industries. Among his many contributions to science in the field of wind and timber engineering and most relevantly for this dispute, he chairs the Technical Committee BD/99, Wind loads on housing for Standards Australia (AS 4055), is a member of the sub-committee BD/6.2 Wind loading for Standards Australia (AS 1170.2) and a member of the Technical Committee TM/10 Design of Timber Structures, Standards Australia.[10]
[10]Exhibit 31, Appendix C.
Dr Boughton is without doubt pre-eminent in his field. He is more than well qualified to express opinions on wind loading.
His evidence in chief is found in Exhibit 31.
I reject the builder’s criticism of Dr Boughton that on questions in respect of which he and Mr Wright differed he attempted to justify conclusions by selective reliance on parts of, or subjective interpretation of, the relevant Australian Standards. Dr Boughton provided careful and detailed explanations of the science behind the Standards and where he had different opinions to those held by Mr Wright provided considered explanations for the reasons for the difference. He was not intransigent and was prepared to modify his opinions when persuaded to do so by the opinions advanced by Mr Wright, e.g., relating to shielding.

Wright

The builder relied on expert evidence from Mr Wright. He holds a Bachelor of Engineering (Civil) obtained in 1976. He has been a member of the Institution of Engineers Australia since 1980. He is registered as a professional engineer in Queensland. Since the early 1990s he has been involved in the investigation of various forms of building failures involving geotechnical, structural and building issues.[11]
[11]Exhibit 38.
His evidence in chief is found in:
(a)his report regarding footings and other structural issues dated 3 July 2020;[12]
(b)his report attaching LiDAR data and contour details derived therefrom dated 28 July 2020;[13]
(c)his report dated 13 October 2020, responding to Dr Boughton’s report;[14] and
(d)a schedule showing topographic calculations and some photographs.[15]
[12]Exhibit 35.
[13]Exhibit 36.
[14]Exhibit 37.
[15]Exhibit 33.
He was cross-examined in relation to footings and other structural issues on 13 April 2021.
I note the owner’s submission that Mr Wright is a ‘professional witness’ called instead of the original design engineer. It is a matter for each party how it chooses to run its case. Typically, it is the case that the tribunal finds greater assistance from an independent expert than a witness of fact, as the original engineer would be.
I find that Mr Wright is qualified to express opinions on wind loading, footings and other structural issues.
I reject the owner’s criticism that Mr Wright provided dogmatic evidence and only made concessions as he gave his evidence. I found his written reports considered. I appreciated his engagement in the intellectual discussions with Dr Boughton. He concurred with most of the reasoning advanced by Dr Boughton and made proper concessions at the appropriate time. I accept the builder’s submissions that Mr Wright took a practical and common-sense approach to interpretation of the Standards; however, in my view an expert should take an appropriately technical and scientifically reasoned approach to the Standards.

Hutton

The owner relied on expert evidence from Mr Hutton. Mr Hutton holds a Bachelor of Engineering (Civil) with first class honours and is a registered professional engineer in Queensland. He has over 10 years industry experience[16]. He has the qualifications and experience to express expert opinions on civil and structural engineering issues in this case. He is not expert in design wind speed analysis. He based his opinions about structural integrity on the assumption that the design wind speed analysis carried out by WindTech was correct.[17]
[16]Exhibit 11, [129].
[17]Exhibit 10, [1].
Mr Hutton provided assistance to the owner since May 2019 when he was engaged to provide a desk top design review.
His evidence in chief is found in:
(a)his report dated 7 June 2019;[18]
(b)his report dated 24 April 2020;[19]
(c)his affidavit dated 13 August 2020;[20] and
(d)a letter dated 20 August 2020.[21]
[18]Exhibit 10.
[19]Exhibit 11.
[20]Exhibit 12.
[21]Exhibit 13.
He was cross-examined on 26 and 27 August, 8 and 15 September 2020.
I reject the owner’s submissions that the cross-examination of Mr Hutton was ‘unfair and unhelpful’. The owner was represented by counsel during Mr Hutton’s cross-examination. It was open to Mr Cooke to object to the questioning if he thought an objection warranted. Indeed, on some occasions he did just that. I also reject the suggestion that by the end of his evidence Mr Hutton was ‘clearly exhausted and confused as to what assumptions were facts he had agreed with or not’.
I found Mr Hutton to be a careful, well-prepared expert witness, alert to his obligations to the tribunal. In reports made after his original desktop review, and during cross-examination, he made some frank and proper concessions which I will address in detail when dealing with individual elements of the claim. In other instances, when his opinions were tested in cross-examination, he remained steadfast for reasons he explained.

Helisma

The owner relied on expert evidence from Mr Helisma. Mr Helisma holds an Associate Diploma of Applied Science (Building) and a Master of Construction Management. He holds a QBCC open builder’s licence.[22] He has decades of experience in the residential construction industry in Queensland. He is well qualified and experienced to express opinions regarding construction defects and the quantum of rectification costs.
[22]Exhibit 5, Appendix A.
Mr Helisma approached the task of pricing rectification as if he were a builder submitting a quote for the work to be done.
He provided expert reports dated 24 October 2019[23] and 29 April 2020[24]. He also participated in the production of a joint quantum experts’ report.[25]
[23]Exhibit 5.
[24]Exhibit 6.
[25]Exhibit 7.
Mr Helisma was cross-examined on 25 August 2020.
He also gave joint evidence with Mr Thompson, a quantum expert called by the builder, on 14 and 15 April 2021.
In the builder’s submissions he was criticised for making a scandalous and baseless allegation in an expert report[26] that the builder deliberately ‘downgraded’ the wind category to cut costs. It was submitted that this allegation typified his adopting the role of an advocate rather than an independent expert assisting the tribunal, particularly as to issues of liability. The task of deciding questions of liability is mine. Rather than acting as an advocate I find that Mr Helisma made a poor choice of words in his report. It would have been better had Mr Helisma said, as he confirmed was the case during cross-examination, that he believed that it had been established that the house should have been designed to C3 and based his report on that assumption. I note the builder’s submissions that his evidence was more tempered on issues of quantum.
[26]Exhibit 5.
I proceed on the basis that Mr Helisma’s costings are based on the assumption that there had been a breach of contract and of the statutory warranties. I find that his views were genuinely held based on the material before him at the time. I have the benefit of considerably more material on which to determine the issues in the proceedings and will address conflicts in the quantum evidence when dealing with individual claims below.

Carpenter

The builder relied on expert evidence from Mr Carpenter. He is a licensed building inspector. He holds QBCC licence no. 613563. He has worked in the construction industry since 1973, since 1989 in Australia. He is qualified and experienced to express opinions regarding whether or not work is defective, and the scope of work needed to rectify defective work.
His evidence in chief is found in his report dated 16 March 2020.[27]
[27]Exhibit 45.
He was cross-examined on 12 April 2021. Quite properly, he accepted that when it came to the methodology for rectification, it is essential to have regard to the engineers’ opinions in matters within their expertise.
While Mr Carpenter professed that he was aware his paramount duty was to assist the tribunal, rather than the party who paid his fees, [28] there were instances in which he put the most favourable gloss he could on facts to favour the builder which could not withstand scrutiny. For example,
(a)although he expressed an opinion that it would be possible to nail the cladding board showing 530mm between the nail heads if 45mm studs were used at 450mm spacings, in cross-examination he conceded it would not be good practice;
(b)although he recommended that windows be replaced from inside the house to reduce costs of scaffolding, he failed to explain it would be necessary to remove some cladding around each window during the rectification.
[28]Exhibit 45, [13]

Thompson

The builder relied on expert evidence from Mr Thompson. Mr Thompson is a quantity surveyor. He holds a Diploma of Applied Science (Building) and a Graduate Diploma in Quantity Surveying. He has worked in the construction industry since 1985. He is experienced and well qualified to express an opinion regarding the quantum of rectification costs.
His evidence in chief is found in his report dated 25 June 2020.[29] He provided construction costs for alternative options for rectification of windows and cladding[30] and for internal lining.[31]
[29]Exhibit 49.
[30]Exhibit 50.
[31]Exhibit 51.

He gave joint evidence with Mr Helisma on 14 and 15 April 2021.
Not surprisingly he approached the costing exercise from the point of view of a quantity surveyor, pricing the scope before him using industry rates from Cordells and quotes. While it is not unreasonable for a professional quantity surveyor to approach the task in this way, taking account of the nature of rectification work by allowing an increased margin, it is not the methodology I prefer in this case.

Vision Surveys

The owner relied on evidence from surveying firm Vision Surveys. Their report dated 17 September 2020 was admitted without objection.[32]
[32]Exhibit 28.
Staff employed by Vison Surveys undertook field work to produce detailed survey plans which were used by Dr Boughton and Mr Wright.

Brazier Motti

The builder relied on evidence from surveying firm Brazier Motti. A statement of Peter Murphy[33] and a surveyor’s report[34] were admitted without objection. Data produced was used by Mr Wright and Dr Boughton.

Relevant legislation and Australian Standards

[33]Exhibit 29.

[34]Exhibit 30.

Queensland Building and Construction Commission Act

The contract is a regulated contract under Schedule 1B of the Queensland Building and Construction Commission Act 1991 (Qld) (QBCC Act).
Relevantly, the following provisions apply:
20 Suitability of materials
(1)   The building contractor warrants that all materials to be supplied for use in the subject work—
(a)will be good and, having regard to the relevant criteria, suitable for the purpose for which they are used; and
(b)unless otherwise stated in the contract, will be new.
21 Compliance with legal requirements
The building contractor warrants the subject work will be carried out in accordance with all relevant laws and legal requirements, including, for example, the Building Act 1975.
22 Standard of work and exercise of care and skill
The building contractor warrants the subject work will be carried out—
(a)   in an appropriate and skilful way; and
(b)   with reasonable care and skill.
23 Adherence to plans and specifications
(1)   This section applies to a regulated contract if plans and specifications form part of the contract.
(2)   The building contractor warrants the subject work will be carried out in accordance with the plans and specifications.
25 Carrying out work with reasonable diligence
The building contractor warrants the subject work will be carried out with reasonable diligence.

AS 4055-2012

Australian Standard 4055-2012 (AS 4055)[35] has the stated objective of providing designers, builders and manufacturers of building products that are affected by wind loading, with a range of wind speed classes that can be used to design and specify such products for use in housing, within the limitations imposed in the standard.
[35]Trial bundle p 5137.
AS 4055 imposes five geometric limits on houses to which the Standard might apply. They are:
(a)the distance from the ground level to the underside of eaves is not to exceed 6.0m;
(b)the distance from the ground level to the highest point of the roof is not to exceed 8.5m;
(c)the width, including roofed verandas, excluding eaves, is not to exceed 16.0m;
(d)the length is not to exceed 5 times the width;
(e)the roof pitch is not to exceed 35°.[36]
[36]Clause 1.2.
Wind loads for houses not complying with the geometric limits are outside the scope of AS 4055.[37]
[37]Clause 1.1.
AS 4055 establishes a system of classification with associated design gust wind speeds for the serviceability and ultimate limit states for both cyclonic and non-cyclonic winds. The ultimate limit state for wind class C2 is 61 m/s and the ultimate limit state for wind class C3 is 74 m/s. [38]
[38]Clause 2.1 Table 2.1B.
The selection of wind speed class for a house depends on the conditions at the site of the house. AS 4055 sets out the means by which the following site conditions are determined:
(a)geographic wind speed region;
(b)terrain category;
(c)topographic class;
(d)shielding.[39]
[39]Clause 2.2.
The informative commentary in Appendix A to AS 4055 states:
This Standard has been derived for houses as a group …In general, the level of reliability for the group is similar to that found by applying AS/NZS 1170.2. However, it is recognised that a correct application of this Standard may lead to some houses with more conservative design loads, and others with less conservative design loads.
It is important to categorise each building on a case-by-case basis. Each site should be assessed individually for its wind classification. Each building must be assessed for compliance with geometry and for wind evaluation pressures.[40]
[40]Section A1.1.

AS 1170.2-2011

Australian/New Zealand Standard AS/NZ 1170.2:2011 (AS 1170)[41] has the stated objective of providing wind actions for use in the design of structures subject to wind action. It is to be used where houses do not comply with the stated geometric and other limitations of AS 4055. [42]
[41]Trial bundle p 5037.
[42]Clause 1.1 Note 5 AS 4055 – 2012.
It provides that the procedure for determining wind actions on structures is to:
(a)determine site wind speeds;
(b)determine design wind speed from the site wind speeds;
(c)determine design wind pressures and distributed forces;
(d)calculate the wind actions.[43]
[43]Clause 2.1.

The site wind speeds defined for the 8 cardinal directions are determined by applying the prescribed formulae.[44]
[44]Clause 2.2.
The building orthogonal design wind speeds are taken as the maximum cardinal direction site wind speed linearly interpolated between cardinal points within a sector ±45° to the orthogonal direction being considered.[45]
[45]Clause 2.3.
The note to clause 2.3 provides:
A conservative approach is to design the structure using the wind speed and multipliers for the worst direction…. To simplify the design, this value could then be used as the design wind speed for all directions on the building.
The design wind pressures and distributed forces are determined by applying the prescribed formula.[46]
[46]Clause 2.4.1.
Wind actions are calculated by considering wind from no fewer than four orthogonal directions and by applying the prescribed formula.[47]
[47]Clause 2.5.
The wind direction multiplier in cyclonic regions is:
(a)0.95 for determining the resultant forces and overturning moments on complete buildings and wind actions on structural elements; and
(b)1.0 for all other cases, including cladding and immediate support members.[48]
[48]Clause 3.5.2.
Cladding is defined as material that forms the external surface over the framing of a building.[49]
[49]Section A6.
The exposure multipliers for site conditions related to terrain/height, shielding and topography are calculated having regard to:
(a)the assessment of terrain by reference to prescribed category descriptions,[50]
(b)values given for fully developed profiles;[51]
(c)averaging of terrain categories and terrain/height multipliers when the upwind terrain varies for any wind direction;[52]
(d)shielding parameters determined by applying the prescribed formula;[53]
(e)the hill shape multiplier assessed for each cardinal direction considered, taking into account the most adverse topographic cross-section occurring within a range of directions within 22.5° on either side of the cardinal direction being considered, determined by applying the prescribed formula.[54]
[50]Clause 4.2.1.
[51]Table 4.1.
[52]Clause 4.2.3.
[53]Clause 4.3.
[54]Clause 4.4.2.
Terrain over which the approach wind flows towards a structure is assessed on the basis of the following descriptions:
…
Terrain Category 2 (TC2) Open terrain, including grassland, with well-scattered obstructions having heights generally from 1.5m to 5m, with no more than two obstructions per hectare, e.g. farmland and cleared subdivisions with isolated trees and uncut grass.
Terrain Category 2.5 (TC2.5) Terrain with a few trees or isolated obstructions. This category is intermediate between TC 2 and TC 3 and represents the terrain in developing outer urban areas, or large scale developments with fewer than ten buildings per hectare…
Terrain Category 3 (TC3) Terrain with numerous closely spaced obstructions…The minimum density of obstructions shall be at least the equivalent of 10 house-size obstructions per hectare, e.g. suburban housing…
…
Selection of terrain category shall be made with due regard to the permanence of the obstructions that constitute the surface roughness.[55]
[55]Clause 4.2.1.
Obstruction is defined as:
Natural or man made objects that generate turbulent wind flow, ranging from single trees to forests and from isolated small structures to closely spaced multi-storey buildings.[56]
[56][A33].
The variation with height of the effect (z) of terrain roughness on wind speed (terrain and structure height multiplier (Mz,cat)) is taken from the values for fully developed profiles given in Table 4.1. Intermediate values of height and terrain category use linear interpolation.[57]
[57]Clause 4.2.2.
When the upwind terrain varies for any wind direction an averaging of terrain categories and terrain height multipliers is to be adopted. The terrain height multiplier (Mz,cat) is taken as a weighted average over an averaging distance, depending on the average height of the structure. The formula for the averaging procedure is set out in Clause 4.2.3.
The hill shape multiplier is to be assessed:
… for each cardinal direction considered, taking into account the most adverse topographic cross-section that occurs within the range of directions within 22.5° on either side of the cardinal direction being considered.[58]
[58]Clause 4.4.2

AS 1684.3 – 2010

The Australian Standard for residential timber-framed construction in cyclonic areas is AS 1684.3 – 2010 (AS 1684.3).[59] The Standard specifies requirements for building practice and the selection, placement and fixing of structural elements used in the construction of timber framed Class 1 and Class 10 buildings within the limitations given in clause 1.4.[60]
[59]Exhibit 46.
[60]Exhibit 46, [1.1.1].
Clause 1.16 provides:
Prior to using the Standard, the design gust wind speed and corresponding wind classification shall be determined. It shall include consideration of terrain category building height and topographic and shielding effects (see Clause 1.4.2). The wind classification is the primary reference used throughout this Standard.
NOTE: … The flow chart shown in Figure 7 provides guidance.
The flow chart in Figure 7 reinforces the requirement to first determine the maximum design gust wind velocity under AS 1170 or AS 4055 before referring to Table 1.1 for wind classification.
Clause 1.4.2 addresses wind loads for structural elements. It provides:
For wind loads, the simplified wind classifications for cyclonic areas Cl to C3, as described by AS 4055, shall be used with the corresponding maximum design gust wind speeds given in Table 1.1.
Either AS 4055 or AS/NZS 1170.2 shall be used to determine the wind classification necessary for the use of this Standard.
The wind classifications covered by this Standard shall be determined as follows:
(a) Where the wind classification is determined from AS 4055, the maximum building height limitation of 8.5 m, as given in AS 4055, shall apply to this Standard. The maximum building width is specified in Clause 1.4.5.
(b) Where AS/NZS 1170.2 is used to determine the maximum design gust wind speed, a wind classification shall be adopted in accordance with Table 1.1. The ultimate limit state design gust wind speed determined from AS/NZS 1170.2 shall be not more than 5% greater than the ultimate limit state wind speed given in Table 1.1 for the corresponding wind classification adopted.
NOTES: 1. The determination of the design gust wind speed and wind classification should take into account the building height, terrain category, topographic classification and shielding classification given in AS/NZS 1170.2 or AS 4055.
…
Table 1.1 provides under the heading maximum design gust wind speed:
(a)for wind classification region C2, the ultimate limit state is 61m/s; and
(b)for wind classification region C3, the ultimate limit state is 74m/s.
Where the wind classifications are determined from AS 4055 the maximum width of a building, excluding eaves is 16,000 mm.[61]

The contract

[61]Exhibit 46, [1.4.5].

General conditions

On 4 October 2017 the owner and a representative of the builder signed a residential building contract (the contract).[62]
[62]Exhibit 42, [JG – 12].
The order of precedence of the contract documents was relevantly:
(a)special conditions set out in Part J of the Appendix;
(b)the general conditions;
(c)the Specifications;
(d)the Plans, and
(e)other contract documents.[63]
[63]Clause 3.3 of the general conditions.
The builder warranted that it would carry out the work:
(a)in an appropriate and skilful way;
(b)with reasonable care and skill;
(c)in accordance with the Plans and Specifications;
(d)with reasonable diligence, and
(e)in accordance with all relevant laws and legal requirements, including the Building Act 1975.[64]
[64]Clause 10.1 of the general conditions.
The statutory warranties provided by part 3, division 2 of Schedule 1B of the Queensland Building and Construction Commission Act 1991, formed part of the contract.[65]
[65]Clause 25 general conditions of contract.
The builder was responsible for obtaining building approval.[66]
[66]Clause 5.1 and Schedule Item 14.
The date for commencement of the works was within 10 business days of the builder receiving various approvals and notices, including building approval.[67]
[67]Clause 8.1(b) of the general conditions.
The prescribed process for practical completion involved the following steps:
(a)the builder giving the owner a final inspection notice not less than five business days before the day on which the builder anticipated bringing the works to practical completion;
(b)the parties attending a final inspection on a mutually agreed time and day;
(c)the builder giving the owner a list of defects identified at the mutual inspection stating which defects it would remedy and when that would occur.[68]
[68]Clause 17 of the general conditions.
Practical Completion is defined as the stage of the Works when:
The Works are completed in compliance with this Contract, including all Plans and Specifications and all statutory requirements applying to the Works, without any defects or omissions other than minor defects or minor omissions that will not unreasonably affect occupation; and
If the Owner claims there are minor defects or minor omissions, the Contractor gives the Owner a defects document for the minor defects or minor omissions;[69]
[69]Clause 1 of the general conditions.
The builder was required to remedy agreed defects in a reasonable period.[70]
[70]Clause 17.6 of the general conditions.
If the builder failed to bring the works to practical completion by the Date for Practical Completion (DfPC) the owner had an entitlement to claim liquidated damages (LDs) at a rate of $50 per day.[71] The DfPC was to be the last day of a 180-day period after commencement.[72]
[71]Clause 18 of the general conditions and Schedule item 18.
[72]Schedule item 10 of the contract.
The builder had the right to claim extensions of time in certain circumstances.[73]
[73]Clause 15 of the general conditions.

Specifications

The contract included an 8 page specification. The builder was to provide ‘full working drawings’.

Plans

The contract included 14 plans supplied by the builder and prepared by Etchd Building Design.[74]
[74]Schedule Item 7(a).
Each of the 14 contract Plans was marked:
Preliminary. Not for construction. Plans are subject to change to comply with relevant covenant & building certification approvals. Building methods, materials & plan re-arrangement are also subject to change. Building designer & builder may change plans to suite (sic) the above at any time.
Each of the contract Plans bore a note that required compliance with local authority, standard building bylaw and all relevant Australian Standards and legislation.
Three of the 14 contract Plans bore the notation: ‘WIND CATEGORY C2’:
(a)Site plan drawing DD 02 rev 11;
(b)Floor plan DD 03 rev 11; and
(c)Floor plan DD 04 rev 11.[75]

The wind classification issue

[75]Exhibit 42, [JG-12].

Pre-contract background

Although resolution of this issue turns on interpretation of the contract, it is useful to set out the history of the contract negotiations to provide background.
In 2013 the developer of the subdivision had concept plans for lot 155 prepared.[76] Those concept plans designated the wind category as C3. Neither the builder,[77] nor the owner was involved in the preparation of those concept plans.
[76]Exhibit 42, [JG – 7].
[77]Exhibit 42, [9].
In August 2017, while the building contract was being negotiated, the builder engaged a building designer to prepare plans for the house based on the developer’s original plans.[78]
[78]Exhibit 42, [12].
Between August and September 2017, a series of revisions of the plans were created, up to revision 9.[79] Each of those revisions designated the wind category as C3.
[79]Exhibit 42, [13].
In early to mid-September 2017, as was its usual business practice, the builder had the design wind classification for the site and structural design for the proposed house assessed by a structural engineer.[80] At 3:24pm on 26 September 2017 an employee of the builder sent an email to Northern Engineering enquiring about the wind classification for lot 155. At 10:52am the following morning, a senior engineer at Northern Engineering responded:
After having completed a review from first principles we would be content to certify the structure for a C2 wind speed.[81]
[80]Exhibit 42, [17].
[81]Exhibit 16, [MA202007-09].
There was no evidence from the engineers as to how the first principles review was carried out.
On 29 September 2017 the owner emailed the builder the owner’s mark up of revision 9 of the plans.[82] The wind category in revision 9 of the plans had been changed from C3 to C2. The owner did not make any mark-up regarding the wind category.
[82]Exhibit 16, [MA202007-07].
As a matter of logic, revision 10 of the plans must have been created between 29 September 2017 and 3 October 2017. Only 2 sheets of the rev 10 set of plans were put into evidence. [83]
[83]Exhibit 16, [MA202007-06].
In the afternoon of 3 October 2017, the builder emailed revision 11 of the plans to the owner.[84]
[84]Exhibit 2, [73].
On 4 October 2017 the owner attended the builder’s office to sign the building contract. The owner’s evidence was that he felt flustered by the extent of the changes and did not query the change in wind classification.[85]
[85]Exhibit 1, [56].
The owner stated that although revision 11 of the plans was said to incorporate all the changes marked up by him, that was not so.[86] The owner and a representative of the builder made and initialled hand written changes and substituted 2 sheets of revision 11 with revision 10.
[86]Exhibit 2, [68].
Mr Gedoun’s evidence was that on a few occasions he mentioned to the owner that the site was classified C2, not C3. [87] The owner’s evidence was that there may have been a minor mention of the classification.[88]
[87]Exhibit 42, [19].
[88]Transcript 1-89.

As the issue of site classification did not assume any importance until after the house was built, it is not surprising that neither gentleman has any particular recollection regarding what was, or was not, said about it. In any case it matters not what was said, or not said. The parties are bound by the terms of the contract they signed.

For construction drawings

As required by the Specification, the builder engaged Etchd to prepare final detailed drawings for the house. [89]
[89]Exhibit 42, [46].
Etched prepared drawings numbered WD01 to WD23. Revision C of the drawings was dated 4 December 2017.[90]
[90]Exhibit 42, [JG – 18].
The notes on drawing WD 01 rev C, general notes and front façade, stated:

General
3 Comply with local authority, standard building law and all relevant Australian Standards & legislation.
…
Construction
2 Roofing battens to be supplied and installed to manufacturers specifications.
3 Batten spacing to manufacturers specifications.
4 Provide roof trusses designed by truss manufacturer to suit nominated wind category.
5 Bracing of trusses to be in accordance with truss manufacturers specifications.
Drawings WD 02 rev C, WD 03 rev C, WD 04 rev C and WD 05 rev C identified the wind category as C2.
The overall dimensions of the house on Drawing WD13 rev C were 16380mm by 17430mm. [91]
[91]Exhibit 42, [JG – 18].

The builder engaged Northern Consulting Engineers to prepare engineering drawings and specifications for the house. [92]
[92]Exhibit 42, [24].
Northern Consulting Engineers issued a Form 15 Compliance Certificate dated 15 December 2017 covering, inter alia, footings, timber joists, steel bearers, bracing, timber load bearing walls and truss tie-downs.[93] Items listed as relied on as the basis of the certification included: ‘AS1170.0, 1-2002, 2-2011, … AS4055-2012, … publications by Lysaght… manufacture bracing design manuals … Design considerations included wind design for C2… truss hold down report 7997 – 4/12/2017.
[93]Exhibit 42, [JG – 18].
The truss hold down report 7997 referred to in the Form 15 was a reaction report (limit state design) for the trusses at lot 155 Elford Place (quote number 7997) prepared by Supatruss and dated 4 December 2017.[94] The report specified truss types, spans, supports, required tie downs and bearing member supports. Desmond Summers of Supatruss issued a Form 15 Compliance Certificate covering roof truss design and manufacture which referred to the specifications in quote 7997.[95] Items relied on as the basis of the certification included ‘AS1170.0’. The reference documentation was ‘Multinail engineering report pages and Multinail truss layout page’.
[94]Exhibit 42, [JG – 17].
[95]Exhibit 42, [JG – 17].

Approved drawings

On 8 January 2018 Regional Certification Group issued a development application decision approving construction of the house based on the designs prepared by Etchd and Northern Consulting Engineers.[96] Condition 8 of that approval required: ‘The structural aspects of this application must comply with the Requirements of C2’.
[96]Exhibit 42, [JG – 18].

Complaint to QBCC

In about November 2018 the owner lodged a complaint about various matters with the QBCC. The list of items complained about prepared by the QBCC does not mention wind classification, but lists issues regarding certificates as contractual matters.[97]
[97]Exhibit 15, [MA-005].
The owner stated that at a meeting with the QBCC in December 2018 the builder produced a Form 15 Compliance Certificate dated 27 September 2018 relating to site wind speed.[98] A complete copy of that Form 15 was attached to Mr Gedoun’s statement.[99] Mr Messer of Northern Consulting Engineers certified that the relevant Australian Standard was AS 1170 and that the cardinal direction site wind speed was 56 m/s.
[98]Exhibit 1, [26].
[99]Exhibit 42, [JG – 17].

Allegedly incorrect wind classification

Mr Gedoun’s evidence was that the first occasion on which he became aware of the owner’s allegation that the site wind classification provided by the engineers was allegedly incorrect was when the builder’s solicitors received a letter from the owner’s solicitors on 28 June 2019,[100] almost a year after construction had ended.
[100]Exhibit 42, [135].
The owner had formed the view that the C2 site wind classification was incorrect based on the expert opinion of Mr Hutton of FortisEM, who in turn relied on a report from WindTech Consultants Pty Ltd which investigated the classification and design wind speed for the property.[101] Windtech had provided a report on the site wind climate dated 20 February 2019.[102] The report classified the site-specific wind classification under AS 4055 as C3 and the site-specific design wind speed under AS/NZ 1170 as 68m/s.
[101]Exhibit 1, [40].
[102]Exhibit 15, [MA-009].

Mr Hutton conducted a full design review to determine if the house was structurally adequate for the design wind speeds calculated by WindTech. In his opinion, dated 7 June 2019,[103] the design was insufficient and inadequate in the following ways:
[103]Exhibit 10.
(a)insufficient battens in the 1200mm edge zones to support roof sheeting;
(b)trusses certified to C2, not C3;
(c)specified truss connections inadequate;
(d)inadequate stud spacing and fastener installation in the Axon cladding;
(e)inadequate stud spacing and fastener installation in the Scyon cladding;
(f)inadequate batten spacing for the eaves in the 1200mm corner zones;
(g)inadequate roller door (specified to C2, not C3);
(h)all windows need replacement as specified to C2, not C3;
(i)inadequate spacing for common studs for external cladding;
(j)inadequate bathroom lintel;
(k)inadequate lintel trimmers to bathroom, southern kitchen and sliding glass;
(l)external bottom plates inadequate for the load;
(m)Smartjoist and cyclone rods connections in some places need rectification; and
(n)absence of necessary certifications for truss support beams and eave overhang blocks.
The builder engaged Peter Wright of Hughes, Beal & Wright Pty Ltd, consulting engineers, to prepare a desk top review into the wind classification for the site. It was Mr Wright’s opinion that the site wind classification was C2 as defined in AS 4055.

Dr Boughton’s opinion – Exhibit 31

Dr Boughton set out his opinion regarding wind actions at the site in his report dated 17 September 2020,[104] which annexed a previous report he had made regarding his review of the wind classification.
[104]Exhibit 31.
In the previous report Dr Boughton summarised his opinion as follows:
(a)as the house does not satisfy two of the limitations on building geometry set by AS 4055: height from natural ground to the underside of the eaves and width, AS 4055 cannot be used to evaluate the wind classification;
(b)the designers could have used AS 1170 to determine the wind speeds and pressures for the site and then determined an equivalent AS 4055 site wind classification;
(c)although there is no documented process for converting AS 1170 wind speeds to an equivalent AS 4055 classification, the designers could have:
(i) used the highest pressures on the building envelope to choose a wind classification that would lead to equal or higher pressures on the same element; or
(ii) selected the highest of the four envelope design wind speeds from AS 1170 and matched it to table 2.1 of AS 4055;
(d)the site has a wind classification of C3 under AS 4055.[105]
[105]Exhibit 31, Appendix D.
In forming his opinion that the width of the house exceeded the permissible width under AS 4055, Dr Boughton had regard to:
(a)approved drawing WD 13 rev C;[106] and
(b)as constructed drawings.[107]
[106]Exhibit 31, Figure 1.
[107]Exhibit 31, p. 5.
In forming his opinion that the height to eaves of the house exceeded the permissible height under AS 4055, Dr Boughton had regard to:
(a)scaled height from approved drawing WD 08 rev C;[108] and
(b)as constructed surveys.[109]
[108]Exhibit 31, Figure 1.
[109]Exhibit 31, Figure 3.
He took his measurements from the natural ground line, which in his opinion is what is required in accordance with Figure 1.1 of AS 4055.[110]
[110]Exhibit 31, Appendix D.
Dr Boughton disagreed with Mr Wright’s suggestion[111] that raising the finished ground level by adding fill in the south west corner of the building would reduce the maximum eave height above the ground level to less than 6 metres under the parts of the eaves that exceed 6.0m above the ground. Dr Boughton observed that it is not possible to affect the height of the eaves from the natural ground line by placing additional fill on the site.[112]
[111]Exhibit 37, [2.4.6].
[112]Exhibit 31, Appendix D.
Dr Boughton explained the reasons, in his view, it is unacceptable to apply AS 4055 if any geometric limit is exceeded. Because AS 4055 is a simplified standard based on AS 1170 it makes a number of assumptions which are only valid for houses that meet the geometric limitations. As the geometric limitations are presented to one decimal place, that indicates the limit of freedom of interpretation to one decimal place. Further, because AS 4055 incorporates a mixture of conservative and unconservative assumptions and a ‘grace’ margin of 5%, users who fail to rigorously interpret the Standard will lose the balance between conservative and unconservative assumptions. [113]
[113]Exhibit 31, Appendix D, Section 7.
If the house fell within the geometric limitations of AS 4055, then based on information available at the time the design was done, and applying the following parameters, Dr Boughton was of the opinion the wind classification was C3:
(a)Townsville is in wind region C;
(b)terrain category 2 was appropriate for the site;
(c)the topographic classification was T3; and
(d)although the site is fully shielded it could only be awarded its classification based on the maximum allowable shielding, i.e., partial.[114]
[114]Exhibit 31, p.11.
Dr Boughton also considered LiDAR based information about contours which had not been available at the time the design was done, but did not change his opinion about the topographic classification.[115]
[115]Exhibit 31, p. 9.
Dr Boughton noted that evaluations using AS 1170 do not result in a wind classification. They require detailed evaluation of wind actions from eight cardinal directions to calculate the design wind speed on each face of the building, which are converted to pressures based on the shape and size of the building, which in turn are used to determine forces on building elements and to order cladding and windows that have the capacity to resist those pressures.[116]
[116]Exhibit 31, p. 13.
Dr Boughton’s calculations using the formula prescribed by AS 1170 were that the maximum design wind speed was 68.4 m/s for the south and west faces of the building. [117] The parameters Dr Boughton applied to perform the calculations were:
(a)Townsville was in wind region C;
(b)the average roof height taken above the natural ground level under the centroid of the building footprint was 5.5m;
(c)terrain categories evaluated by quadrant as set out in Table 2 of his report;
(d)shielding multiplier evaluations by quadrant as set out in Table 3 of his report; and
(e)topographic multiplier evaluations by quadrant using LiDAR 1m contours as set out in Table 5 of his report.
[117]Exhibit 31, p.20.
In his opinion, cladding elements with a wind classification of C3 are required to resist wind speeds of 68.4 m/s.[118]
[118]Exhibit 31, p.20.
Dr Boughton observed that elements specified as C2 wind classification will only resist wind speeds of 61 m/s.[119]
[119]Exhibit 31, p.21.
Dr Boughton observed that there is no documented process for converting AS 1170 wind speeds into an equivalent AS 4055 wind classification. He suggested two ways that a designer might make the conversion:
(a)use the envelope design wind speeds to determine pressures on the building envelope elements, using the highest of the pressures to choose a wind classification that will lead to equal or higher pressures on the same element; or
(b)select the highest of the four envelope design wind speeds from AS 1170 and match them to table 2.1 of AS 4055 to the wind classification that will give an ultimate wind speed that is equal to or greater than the selected envelope design wind speed.[120]
[120]Exhibit 31, Appendix D.
Dr Boughton noted that if the whole building was designed to AS 1170 there may be other differences in pressures compared to those derived using AS 4055 as local pressure zones in designs using AS 1170 are a function of building geometry and will be significantly larger than the nominal areas presented in Figures 3.1. and 3.2 in AS 4055.[121]
[121]Ibid, [4.4].

Mr Wright’s opinion – Exhibit 37

Mr Wright responded to Dr Boughton’s report in a report dated 17 September 2020.[122]
[122]Exhibit 37.
Mr Wright agreed that the house does not satisfy two of the limitations on building geometry set by AS 4055, however was of the view that:
(a)it was not unreasonable, unsafe or unconservative to ignore a 1% exceedance of the building width limit for 12% of the length of the building; [123]
(b)83% of the eaves length lie within the 6 metre height limit;[124] and therefore it was reasonable, safe and not unconservative for the designer to have used AS 4055 given the limited area of eaves exceeding the 6m height limit.[125]
[123]Exhibit 37, [2.2.10].
[124]Exhibit 37, [1.1.4].
[125]Exhibit 37, [2.3.14].
He disagreed with Dr Boughton’s use of the natural ground line as the point from which the height measurement should be taken, on the basis that AS 4055 does not refer to the natural ground line. Mr Wright based his measurement from the horizontal surface of the ground at the side of the house at completion, i.e. the finished ground level.[126]
[126]Exhibit 37, [2.4.14].
Mr Wright concluded that AS 4055 could be used because:
(a)the commentary on the Standard states:
This Standard has been derived for houses as a group or large number of buildings. In general, the level of reliability for the group is similar to that found by applying … AS 1170. However, it is recognised that a correct application of this Standard may lead to some houses with more conservative design loads, and others with less conservative design loads.
(b)it provides a less complicated procedure for determining a site wind classification;
(c)the peak design wind gust has a duration of 0.2 seconds;
(d)the annual probability of exceedance is 1 in 500; and
(e)as an experienced and cautious practitioner, regularly using Australian standards in real world applications, he considered it appropriate, safe and not unconservative to use AS 4055.[127]
[127]Exhibit 37, [2.4.18].
In Mr Wright’s opinion the site wind classification carried out in accordance with the procedures set out in AS 4055 is C2.[128] He applied the following parameters:
(a)Townsville was in wind region C;
(b)terrain category 2.5 (not TC2) was appropriate for the site;
(c)the topographic classification was T1 because the site is not in the top third of the hill; and
(d)the site is fully, not partially shielded.
[128]Exhibit 37, [1.3].
Mr Wright opined that Dr Boughton’s classification was based on incorrect inputs including:
(a)assessment of the terrain category to the south and west of the site;[129]
(b)identification of the RL of the bottom of the hill as 15m;[130]
(c)choosing RL 42m as the top of the hill when the highest point on the hill is 43m;[131]
(d)using the floor level of the house, not the site level, to assess topographic classification;[132]
(e)adopting topographic classification T3 which only allows for partial shielding.[133]
[129]Exhibit 37, [2.5].
[130]Exhibit 37, [2.7.6].
[131]Exhibit 37, [2.8.8].
[132]Exhibit 37, [2.13].
[133]Exhibit 37, [2.14].
The disagreement about the RL of the top and bottom of the hill inevitably leads to a difference in calculation of the maximum slope in the top half of the hill which results in a different topographic classification.[134]
[134]Exhibit 37, [2.11].
In Mr Wright’s opinion, under AS 1170, the maximum design wind speed at the time of original design was 64.0 m/s.[135] When he took account of the shielding provided by two houses recently constructed nearby, his opinion was that the maximum design wind speed from the east and south was 61.4 m/s.[136]
[135]Exhibit 37, [1.6].
[136]Exhibit 37, [3.5.5].
Mr Wright observed that different procedures are used to derive wind pressures on various building elements. He agreed with Dr Boughton that when designing using AS 1170 local pressure zones are a function of geometry whereas when designing using AS 4055 local pressure zones are of fixed dimensions.[137]
[137]Exhibit 37, [3.511].
He referred to AS 1684.3, the Australian Standard for residential timber-framed construction, noting that where AS 1170 is used to determine the maximum design gust wind speed, Table 1.1 equates an ultimate limit state wind speed of 61 m/s to a wind classification of C2. He then applied a 5% allowance to equate a site design wind speed of up to 64 m/s to a site wind classification of C2 for the design of the timber frame.[138]
[138]Exhibit 37, [4.7] – [4.9].
Based on his years of experience Mr Wright observed that most manufacturing and building processes have inherent redundancies built in which almost invariably make elements resistant to greater loads than the minimum design load. The ultimate capacity of the building element is determined as the load at which only a small percentage of samples of the material will fail. He observed that in the case of wind load the application of a load higher than the design wind load would result in a momentary exceedance of the design capacity. He suggested that this was the likely basis for the allowance of wind speeds 5% higher than the basic 61 m/s wind speed defining wind classification C2 in AS 1684.3.[139]
[139]Exhibit 37, [3.5.7].

Joint report of wind experts – Exhibit 32

Dr Boughton conferred with Mr Wright on 22 October 2020 and together they produced a joint report in which they identified areas of agreement, areas of disagreement and the reasons for their differences of opinion.[140]
[140]Exhibit 32.
The experts agreed that the house is within three of the five geometric limits prescribed by AS 4055, in respect of:
(a)height;
(b)aspect ratio; and
(c)roof slope.[141]
[141]Exhibit 37, [2.1].
The experts agreed that at design stage the eaves exceeded 6.0m.[142] The experts also agreed that as built the eaves exceed 6.0m.[143]
[142]Exhibit 32, [1.2.1].
[143]Ibid, 1.3.1.
The experts disagreed about the location of the ground level from which the measurement of the distance to the underside of eaves is to be taken. In Dr Boughton’s opinion the measurement of the distance from the ground level to the underside of eaves is to be taken from the natural ground line. [144] In Mr Wright’s opinion the measurement of the distance from the ground level to the underside of eaves should be taken from the designed finished ground level, not by ignoring designed cut and fill. [145]
[144]Ibid, 1.3.2.2.
[145]Ibid, 1.3.3.
Dr Boughton’s opinion is based on his interpretation of clause 1.2(a) and the sections in Figure 1.1 of AS 4055. He says that the Figure shows local cut and fill to demonstrate that it is excluded from the ground line in the context of the application of clause 1.2.[146] Mr Wright’s interpretation is based on an alternative reading of Figure 1.1 of AS 4055, supported by a similar diagram at Figure 1.1 in AS 1684.3-2010, which shows the measurement from the horizontal line. [147] He observes that if it was not the intention of AS 4055 that the eaves height be measured from the horizontal line outside the building wall on the low side of the building in Figure 1.1, the inclusion of the line is superfluous and misleading.[148]
[146] Ibid, 1.3.2.2.
[147]Ibid, 1.3.3.
[148]Exhibit 32, 1.3.3.

Dr Boughton acknowledged that some readers of AS 4055 have interpreted Figure 1.1 as Mr Wright has done. He noted that the forthcoming version of AS 4055 will address this issue.[149]
[149]Exhibit 31, Appendix D.
AS 4055 prescribes that the width, including roofed verandas, excluding eaves, is not to exceed 16.0m. The experts agreed that the maximum building width is 16.18m.[150]
[150]Exhibit 32, [1.1.1].
In Dr Boughton’s opinion the prescribed dimensions are absolute,[151] therefore AS 4055 should not have been used to award a wind classification to the house because as designed the house exceeded two of the five geometric limits prescribed by AS 4055.[152] Mr Wright disagreed because in his opinion, for all practical purposes, AS 4055 could be used to provide a wind classification.[153]
[151]ibid, [1.2.2.1].
[152]ibid, [2.1.1].
[153]Exhibit 32, [2.2].
Mr Wright is of the opinion that AS 4055 could have been used to award a wind classification to the house, because:
(a)a 1% exceedance of the width limit for 12% of the building length for all practical purposes ought not exclude the application of AS 4055;[154]
(b)applying a high precision to a limitation, ie 16.0m on the building width, is inconsistent with the inexact art of trying to determine a wind speed at this location which has a 1 in 500 year probability of occurring and has a duration of 0.2 seconds;[155]
(c)the 6.0 height limit is only exceeded in one corner of the building; 88% of the length of the eaves is less than 6.0m above finished ground level.[156]
[154]Exhibit 32, [1.1.3.1].
[155]Ibid, [1.1.3.3].
[156]Ibid, [1.2.3.1].
The experts agreed that for the purpose of determining wind action under AS 1170 by:
(a)determining site wind speeds;
(b)determining design wind speed from the site wind speeds;
(c)determining design wind pressures and distributed forces, and
(d)calculating wind actions
the site lies in Wind Region C[157] and that the regional wind speed is 69.3m/s.[158]
[157]Ex 32, [15.1].
[158]Exhibit 32, [16.1].
It was common ground that the building height is 5.3m.[159]
[159]Ibid, [17.1].
While the experts agreed that the Terrain Category (TC) from the north is TC2.5 and from the east is TC3,[160] they disagreed about the predominant Terrain Category beyond the lag distance to the south, south west and west. Dr Boughton’s opinion is that much of it is TC2, not TC2.5.[161] Mr Wright’s opinion is that it is TC2.5, not TC2.[162]
[160]Ibid, [18.2].
[161]Ibid, [4.2], [18.3].
[162]Ibid, [18.4].
Dr Boughton’s opinion is based on:
(a)the description of terrain categories in clause 2.3 of AS 4055; and the commentary on terrain categorisation in clause A3.2 of Appendix A to AS 4055; [163]
(b)the fact that the terrain category descriptions in AS 4055 and AS 1170 are identical;
(c)his opinion that the area south and west of the subdivision does not fit the description of TC 2.5, i.e. does not have scattered houses or large acreage developments;[164]
(d)the open nature of the vegetation to the south and west, which is likely to become thinner over time due to burning;[165] and
(e)his analysis of street view and satellite images.[166]
[163]Exhibit 32, [4.2].
[164]Ibid, [18.3.2].
[165]Ibid, [18.3.3].
[166]Ibid, 4.2.
Mr Wright’s opinion is based on:
(a)the description of terrain category 2.5 in clause 4.2.1(d) of AS 1170, i.e. terrain with a few trees or isolated obstructions;
(b)the fact that ‘tree’ is not defined in AS 1170;
(c)the Oxford dictionary definition of tree;
(d)his opinion that there are more than a few trees to the south and west,[167] as shown in photographs of the terrain he took on 28 August 2020.[168]
[167]Ibid, [18.4].
[168]Exhibit 37, [Appendix A].
As a consequence of the disagreements regarding terrain category to the south, south west and west, Dr Boughton’s [169] and Mr Wright’s [170] calculations of the terrain category multipliers for the various sectors differ.
[169]Ibid, [18.3.4].
[170]Ibid, [18.4.8].
The experts agreed that at the time of design there were 10 shielding buildings around the site.[171] The experts agreed that by the time they prepared the joint report (October 2020) two additional buildings had been constructed, a house to the south west and another house to the west.[172] They recalculated the shielding values for each wind direction to take account of the two additional houses.
[171]Ibid, [19.1].
[172]Ibid, 20.1
The experts disagreed about the contribution to shielding of buildings that straddled sector boundaries, in particular to the west and north west. Dr Boughton assigned one shielding house to each of the west and north west quadrants.[173] Mr Wright assigned two shielding houses to each of the west and north west quadrants.[174]
[173]Ex 32, [20.2].
[174]Ex 32, [20.3.1].
Dr Boughton assigned buildings that straddle sector boundaries to the sector that had the majority of the roof area of the building.[175] Mr Wright believed that buildings that straddle sector boundaries contribute to shielding for wind in each of the sectors on either side of the boundary.
[175]Ex 32, [19.2.2].
Dr Boughton’s approach was based on:
(a)the definition of buildings that provide shielding in clause 4.3.2 of AS 1170, i.e., only buildings within a 45° sector of radius 20h (symmetrically positioned about the directions being considered) and whose height is greater than or equal to z shall be deemed to provide shielding;
(b)his conclusion that any building that may have been 2 storeys or with a wall height of around 6m as potentially shielding.[176]
[176]Ibid, [19.2].
Mr Wright’s opinion was based on:
(a)the fact that AS 1170 is silent on how to manage the shielding effect of buildings that straddle sector boundaries;
(b)avoiding an excessively conservative outcome which would result if neighbouring buildings that straddle sector boundaries were ignored.[177]
[177]Ibid, 20.3.
The experts agreed on the methodology for calculation of the topographic multiplier but used different reference positions for the site.[178] Dr Boughton used the location of the house on the site that characterised the floor elevation relative to the topography.[179] Mr Wright used the centroid of the building footprint as the reference position for calculation of the topographic multipliers.[180]
[178]Exhibit 32, [21.1].
[179]Ibid, [21.1.1].
[180]Ibid, [21.1].
Dr Boughton’s data points for the top of the slope and the bottom of slope[181] differ from Mr Wright’s data points for the top of the hill and the bottom of hill.[182] Mr Wright analysed the cross sections with the aid of AutoCAD taking the highest point on the cross section as the top of the slope.[183]
[181]Ibid, [21.1].
[182]Ibid, [21.5].
[183]Ibid, [21.4].
The experts agreed on the methodology to arrive at the design wind speed.[184] However, as Dr Boughton and Mr Wright used different terrain categorisations and topographic multipliers it is inevitable that each arrived at a different design site wind speed. Using LiDAR data and considering only those houses eligible for shielding at the time of the design, Dr Boughton calculated the design site wind speed for the house at 71.5 m/s.[185] Mr Wright calculated the design site wind speed for the house at 64 m/s.[186]
[184]Ibid, 22.1.
[185]Ibid, 22.3.1.
[186]Ibid, 22.4.
Taking account of the two extra shielding buildings constructed after the design was done, Dr Boughton recalculated the design site wind speed for the house at 68.1 m/s.[187] Mr Wright recalculated the design site wind speed for the house at 61 m/s.[188]
[187]Exhibit 32, [22.3.2].
[188]Exhibit 32, [22.4.2].
The experts agreed that design wind speed derived using a wind direction multiplier of 1 is the wind speed to be used to determine wind classification.[189] As a consequence of deriving different design wind speeds the experts disagreed as to the appropriate wind classification.
[189]Exhibit 32, [23.1].
Dr Boughton said that at the original design stage the design wind speed was 71m/s (rounded from 71.5 m/s), hence the appropriate wind classification from table 2.1B of AS 4055 was C3.[190] His view remained unchanged after considering the revised design wind speed of 68 m/s (rounded from 68.1 m/s).[191] Mr Wright said that at the original design stage the design wind speed was 64 m/s. With the two shielding houses he said the design wind speed was 61 m/s, equivalent to a wind class of C2.[192]
[190]Exhibit 32, [23.2.2].
[191]Exhibit 32, [23.2.4].
[192]Exhibit 32, [23.3].
The experts disagreed about the application of AS 1684.3, the Standard for residential timber frame construction. In Dr Boughton’s opinion AS1684.3 cannot be used to derive a general wind classification because it is only appropriate for the design of timber framing, and not for ordering windows, cladding or garage doors. In his opinion those elements require a wind classification from AS 4055.[193] Accordingly, Dr Boughton disagreed with Mr Wright’s opinion that AS 1684.3 equates to a design site wind speed of 64 m/s a wind classification of C2. In Mr Wright’s opinion, at design stage it would have been appropriate to design the timber framed construction of the house to a C2 classification.[194]
[193]Ibid, [23.2.3].
[194]Exhibit 32, [23.3.6].
In summary, the experts disagreed about:
(a)whether AS 4055 should have been used by the designer to give a wind classification to the house as the geometric limits for distance from the ground level to the underside of eaves and width had been exceeded;
(b)design wind speeds calculated in accordance with AS 1170, because each had:
(i)      categorised some of the terrain differently,
(ii)      calculated the topographic multiplier based on different data points for the top of the hill; and
(iii)     calculated different shielding values based on the contribution to shielding of houses that straddle sector boundaries;
(c)whether AS 1684.3 could be used to derive a general wind classification to design the house, i.e., the cladding as well as the frame.

Concurrent evidence of wind experts

Dr Boughton and Mr Wright gave concurrent evidence on 27 and 28 January 2021. I commend the experts for the open and frank manner in which they conducted themselves which assisted me to understand crucial issues for determination in the proceedings.
At the commencement of the first day of concurrent evidence Dr Boughton provided some comments on additional material that had been supplied to him on 25 January 2021.[195]
[195]Exhibit 34.
During the concurrent evidence the experts reached agreement on some additional areas.
The experts agreed that Mr Wright’s suggestion that fill be placed under the parts of the eaves that exceed 6.0m above the ground would have no impact on the wind loads on the house.[196]
[196]Transcript 7-35 to 36.
The experts agreed that if a designer used AS 4055 there would be one wind classification for the site, and all aspects of the building would have had to be designed for that wind classification. Whereas if a designer used AS 1170, the designer could have carried out what Mr Wright described as the laborious process of calculating the wind pressures on all the faces of the building and on all the faces of the roof and designed accordingly. [197]
[197]Transcript 7-57.
The experts agreed that general wind classification for cyclone regions, including Townsville, can be obtained from table 2.1B in AS 4055. They agreed that table 2.1B equates design gust wind speed (m/s) with wind class. It was common ground that having determined the wind speed using AS 1170, a designer may determine an equivalent AS 4055 site wind classification by using the highest design site wind speed.[198]
[198]Transcript 7-73.
The experts explained that cladding elements include windows, timber cladding and the studs to which it is fixed, the garage door,[199] roof sheeting and the battens or purlins to which it is fixed. The trusses and anything below the trusses, which would include the truss-to-wall connections or roof cladding connection to the purlins, lintel trimmers or lintels and footings are structural elements.[200]
[199]Transcript 7-68.
[200]Transcript 7-70.
Dr Boughton agreed that a designer could order cladding, which includes windows, to resist the pressure calculated for a particular face of the house, but noted that design wind speed alone was not sufficient information. He explained the process when using AS 1170 was to first establish the design windspeeds on each of the faces and then to establish pressure coefficients having regard to the unique geometry of the building being considered.[201] Mr Wright concurred.[202]
[201]Transcript 7-63.
[202]Transcript 7-67.
Dr Boughton explained that when windows are ordered, the glazing manufacturer can be given:
(a)a single C classification under AS 4055, or
(b)the design wind pressures calculated as prescribed by AS 1170.[203]
[203]Transcript 7-61.
Dr Boughton accepted that his approach to converting AS 1170 wind speeds into an equivalent AS 4055 wind classification; i.e., selecting the highest of the four envelope design wind speeds from AS 1170 and matching it to the wind classification table 2.1 of AS 4055 to give an ultimate wind speed that is equal to or greater than the selected envelope design wind speed, was a conservative approach .[204]
[204]Transcript 7-55.
Dr Boughton summarised the process that had been undertaken in the joint report as follows:
If you choose to use AS4055, you can use AS4055 in its entirety and derive a wind classification. If you choose or are prevented from using AS4055 and you must – or … opt to use AS/NZS1170 part 2, you can calculate wind speeds, as both Mr Wright and I have done, in accordance with AS/NZS1170 part 2 and allocate a single wind classification based on the 10 highest wind speed that we obtained on the four orthogonal faces of the building. Which is what both of us have done in the joint expert report. [205]
[205]Transcript 7-75.
Mr Wright agreed that if it was assumed that the design wind speeds calculated by Dr Boughton applied, and if the designers ordered the cladding using the classification system under AS 4055, then all the cladding for the house would have had to have been C3.[206]
[206]Transcript 7-60.
Counsel for the builder explored the possibility of identifying which parts of the house might be defective by considering every individual window or door element and calculating a pressure to decide whether or not the product installed is acceptable or not. The experts agreed that would be possible,[207] however, neither of them had undertaken that work.
[207]Transcript 7-68.
The experts agreed that their use of different reference positions for the site for calculation of the topographic multiplier for AS 1170 was a minor difference.[208]
[208]Transcript 7(sic)-95.
During the discussion of shielding in the context of AS 1170, Dr Boughton acceded to the fact that houses constructed since the subject house had been designed to the west and north west quadrants may offer extra shielding to the north-western sector.[209] As a consequence of this concession, over the lunch break, the experts reviewed their calculations of the shielding multiplier. The recalculated shielding multipliers for the west and north-west quadrants became Exhibit 39.
[209]Transcript 7(sic)-75.
Taking account of those changes in the shielding multiplier, each expert again recalculated his site wind speed data. The highest design site wind speed for the house calculated by Dr Boughton was 67.5 m/s from the south and west.[210] The highest design site wind speed for the house calculated by Mr Wright was 61.5 m/s from the east and the south.[211]
[210]Exhibit 40.
[211]Exhibit 41.
While the experts reached agreement on some additional points their opinions continued to differ in other respects.
Quite some time was taken up with a discussion regarding the wind classification that might be attributed if the house came within the dimensions prescribed by AS 4055, in particular exploring the reasons why each expert took a different view regarding topographic classification under AS 4055. At the end of the discussion neither expert altered his position regarding the three variables that have to be considered to select a topographic class from table 2.3 in AS 4055.
During the concurrent evidence it became clear that the fundamental difference between the experts regarding terrain categorisation under AS 1170 arose because of their different approaches to categorising terrain, which each based on his interpretation of AS 1170. Dr Boughton identified the terrain category along a particular line of sight for the orthogonal segment whereas Mr Wright considered the particular terrain proportion in the entire segment.[212] If there was a line of sight that Dr Boughton assessed as TC 2, regardless of the fact there may be more surface roughness in parts of the quadrant, he applied TC 2. Whereas Mr Wright considered the surface roughness in the quadrant and assigned a category to the quadrant.
[212]Transcript 7(sic)-46.
Dr Boughton provided a detailed explanation of the concept of surface roughness, the reason the word “obstruction” is used in AS 1170, what is meant aerodynamically by an obstruction, and the role that trees play as obstructing elements. He explained:
.. it is important to evaluate the wind speed at a lowish height to the terrain – in the air column. In terms of the matters pertaining to houses, that is at a height of about six metres. And there’s a transition between zero – at zero metres and at hundreds of metres, about 200 metres – we’re talking hundreds of kilometres an hour. So it’s very important to work that transition out in order to represent the wind speed at the structure height. And that’s what the terrain categories do. It’s a means of categorising surface roughness that enable wind engineers to choose appropriate factors to determine what the wind speed is at particular heights. Now, the – the mechanism of that transition is turbulence. And as Mr Campbell explained yesterday, if we have an obstruction, which is something solid on the ground, as the wind is going past that obstruction, immediately behind that obstruction – and if it’s a large obstruction like a house, it’s probably easier to – to picture – as the air goes past the obstruction, immediately adjacent to the obstruction, the air is whistling by, but immediately behind the obstruction there is no air movement because the obstruction has stopped it. That causes an eddy to develop and that creates mixing in the airstream which mixes the low wind speed with the high wind speed and it evens the – the wind speed out. So the transition is caused by turbulence that is induced by …– obstructions. And as Mr Campbell pointed out yesterday, it’s what’s happening immediately behind the obstruction that introduces the turbulence. If the obstruction is moderately large, like a – a building, then that introduces a lot of turbulence and that’s able to make a big transition or big change to the transition and slow the air down at this height level. If, on the other hand, the obstruction is something small, like a pole or a tree, then obviously the eddy it can generate is quite small and there is less mixing involved with it.
The words in the standard relate to openness because the more you can see through the landscape, the less or the smaller the turbulence introduced by those obstructions actually is, the less mixing there is and the less transition there is between the high speeds higher in the atmosphere and the zero wind speed at the ground, and hence the wind speed for low-rise structure is higher, so that the rougher the terrain, the bigger and the more plentiful the things that interrupt the air flow, the slower the wind speed is at structure height where the structures are quite close to the ground. So the concept introduced for the low categories in the standard uses the word “openness”. Yesterday, I was using the word “opacity” as the opposite of “openness”. So for the higher terrain categories, then there are large numbers of obstructions that the wind cannot penetrate. Now, in general, if you can see through the landscape, then the wind is going to be able to blow through the landscape and have less interruption.[213]
[213]Transcript 7(sic)-17.

Despite the inaccuracy of the description of item 14 in the Scott Schedule, I will allow $543 being the amount conceded to rectify the tile sill threshold and door joinery.

Protection of patio floor joists (Scott Schedule item 15)

While undertaking his assessment of the builder’s work, Mr Helisma formed the opinion that the floor joists had not been adequately protected to ensure the durability required in the Townsville region.[500] In his opinion all exposed timber above ground should have been treated to H3.[501]
[500]Exhibit 5, [149].
[501]Exhibit 5, [151].
Table B1 of AS 1684.3 describes the exposure for:
(a)hazard class H3 as outside above ground; and
(b)hazard class H2 as inside, above ground.
Table B1 of AS 1684.3 describes the specific service conditions for:
(a)hazard class H3 as subject to periodic moderate wetting and leaching; and
(b)hazard class H2 as protected from wetting and nil leaching.
Table B1 of AS 1684.3 describes the typical uses for:
(a)hazard class H3 as weatherboard, fascia, pergolas, window joinery, framing and decking; and
(b)hazard class H2 as framing, flooring, and similar used in dry conditions.
In cross-examination Mr Helisma was unable to say one way or the other whether the joists were subject to periodic moderate wetting or leaching. He agreed that with the exception of the joists under the roofed patio area to the left-hand side of the building, the joists are covered.[502]
[502]Transcript 2-68.
Mr Carpenter disagreed that the work was defective on the basis it was a contractual matter.[503]
[503]Exhibit 45, [142].
In the Building Experts Joint Quantum Report no quantum was claimed for item 15. However, as part of item 7.3 in the Scott Schedule there was a claim for $2,587.20 for 40 litres of ecological paint finish and $5,900.91 for applying the finish[504] which was said to be necessary to address Mr Helisma’s concerns that the joists needed to be treated to bring them up to an H3 standard.[505]
[504]Exhibit 7, Attachment A.
[505]Transcript 12-165.
I am not satisfied that the joists need to be treated to bring them up to an H3 standard to ensure durability having regard to Table B1 of AS 1684.3. The joists are under cover. There was no evidence that the joists under the covered patio are subject to wetting. I will not allow this claim.

Minor defects (Scott Schedule item 16)

The owner’s claim for minor defects was poorly presented. No attempt was made to reconcile the list of twelve minor defects in Mr Helisma’s report with his costings for the rectification of the minor defects in Appendix 1 to his report. The confusion was exacerbated by the unexplained discrepancies between the report and the Building Experts Joint Quantum report. The owner’s closing submissions made no reference to his claims for rectification of minor defects so provided no assistance in addressing anomalies.
Twelve minor defects were listed in Mr Helisma’s report.[506] They were:
[506]Exhibit 5, [192].
(a)front door aluminium screen door requires adjustment;
(b)front door seals not installed;
(c)non-protection to top of patio deck floor joists;
(d)patio handrails not secured;
(e)stainless steel balustrade wire not terminated in sound condition;
(f)poor coverage of applied clear finishes to timber posts and handrails;
(g)gapping between skirting and floors adjacent to the entry stairs and linen cupboard;
(h)sagging kitchen bench top;
(i)uneven margins around laundry door;
(j)aesthetically unacceptable fall in northern elevation roof gutters;
(k)inconsistent fixings of metal capping flashing to the parapet;
(l)poor paint coverage in numerous spots.
The first two have been addressed at item 14 of the Scott Schedule above.
The QBCC observed that the bow in the kitchen benchtop to the east side of the stove had been resolved.[507]
[507]Exhibit 15, [MA-005].
In Appendix 1 to his report,[508] Mr Helisma set out his costings for the rectification of the minor defects as follows:
[508]Exhibit 5.
(a)grind /acid clean concrete floors;
(b)painting floors, external timber door and internal ceilings;
(c)labour – painter, plasterer, tiler and unskilled;
(d)fibre cement sheeting;
(e)solid core door;
(f)tiles;
(g)setting plasterboard;
(h)roof plumbing - gutters;
(i)laying turf;
(j)carpentry to rectify defects to post, top rail fixing and horizontal wires;
(k)contingency;
(l)location factor;
(m)margin.
The Scott Schedule attached to Mr Helisma’s report claimed $11,790.25 including a 20% contingency, a margin of 20% and a locality cost factor of 13.1%.for rectification of minor defects.[509]
[509]Exhibit 5, [appendix 1].
Mr Thompson did not provide any opinion on the cost of rectification of the minor defects in the Building Experts Joint Quantum report.
The builder denied liability on the bases that either:
(a)the claims were insufficiently particularised; or
(b)arose from a lack of maintenance since completion.
In particular, it was submitted that:
(a)patio handrails, balustrade wire, timber posts and gapping between the skirting boards and the floor are not defective works but are maintenance issues and the owner’s responsibility;
(b)no defect is demonstrated of uneven margins around the door to the laundry;
(c)insufficient particulars of the allegedly inconsistent fixings of metal capping flashing to the parapet had been provided;
(d)as the painting was certified no defect was demonstrated.
The builder made no submissions to the claim that relates to the installation of an epoxy surface to the garage floor. I find it is reasonable for the owner to be awarded the costs of providing a single finish across the entire surface area. Doing the best I can from the itemised costs, I will allow:
(a)$435.05 for grinding/ acid cleaning the floors;
(b)$1,225.00 for epoxy painting the floor;
(c)$145.40 for the painter; and
(d)$511.12 for unskilled labour.
None of the twelve alleged minor defects listed by Mr Helisma suggest that it would be necessary to use 6 metres of 6.0mm FC sheeting to rectify. Accordingly, I see no basis on which I could allow the claim for $361.86 for 6 metres of 6.0mm FC sheeting. Nor was there any identification of the basis of the claim for setting plasterboard. I will not allow the $110.06 claimed.
None of the twelve alleged minor defects listed by Mr Helisma refer to a provision of, or replacement of, a solid core door. Accordingly, I see no basis on which I could allow the claim for $984.62 for a solid core door.
There is no clear nexus between the claim for 4.4m² of wall tiles and any of the twelve alleged minor defects listed by Mr Helisma. Accordingly, I see no basis on which I could allow the claim for $625.37 for tiles.
Mr Helisma said that the fall in northern elevation roof gutters was aesthetically unacceptable. He costed repairs at $795.50. In the absence of any evidence of failure to meet building standards or regulations I will not allow this claim.
I will not allow the claim for $507.60 for 20m² of turf as it appears to duplicate item 17 in the Scott Schedule.
I reject the builder’s submission that the claim regarding rectification of patio handrails, balustrade wire, timber posts and gapping between the skirting boards and the floor are maintenance issues. The owner has been complaining about the balustrade to the deck since he first complained to the QBCC.[510] I will allow the claim for $1,574.75 for carpentry.
[510]Exhibit 15, [MA-005] item 73.
During the joint quantum evidence, Mr Helisma said that he elected to apply a contingency rather than to increase the rates to allow for a small job factor.
As all of these small jobs will be attended to while the rectifying builder addresses all other necessary rectification, I find there is no need for a 20% contingency to be allowed as these will form part of a larger list of rectification tasks in plain sight.
In summary I have allowed a total of $3,891.32 plus a margin of 20% and a locality cost factor of 13.1% for rectification of minor defects.

Reinstate landscaping (Scott Schedule item 12.3)

The owner claims $1,666.73 including a margin of 20% and a locality cost factor of 13.1%.for the reinstatement of the landscaping necessary as a result of damage caused by rectification. Mr Thompson agreed with the claimed cost.[511]
[511]Transcript 12-193.
Having found the builder liable for some of the rectification, it follows that it is also liable for the cost of reinstating consequential damage to the landscaping. I find the owner is entitled to recover $1,666.73 including a margin of 20% and a locality cost factor of 13.1% for the reinstatement of the landscaping.

Preliminaries (Scott Schedule item 17)

The owner claims for:
(a)surveying costs;
(b)certification;
(c)3 months temporary fencing hire;
(d)6 weeks toilet hire;
(e)building site sign;
(f)termite management;
(g)6 weeks skip bin hire;
(h)demolition waste disposal fee;
(i)final site clean;
(j)margin; and
(k)location cost factor.[512]
[512]Exhibit 7, Attachment A.
I reject the builder’s submission that the amount awarded for any preliminaries should be limited to an amount proportional to damages awarded as there is no nexus between the quantum of damages awarded and one off or time related preliminary claims. The site will need to be safety fenced for the duration of the rectification. Waste material will need to be put into a skip and dumped. Workers will need toilet facilities. The termite barrier must be reinstated. The rectification work must be certified. The site will need to be cleaned after the work is done. A period of three months for fencing hire and six weeks for hire of site facilities does not seem unreasonable for the amount of rectification required.
I find that the owner is entitled to recover preliminaries of $10,558.48, being the total claimed including a margin of 20% and a locality cost factor of 13.1%.

Additional engineering design and supervision (Scott Schedule item 18)

The owner claims $18,500 for drafting design and instructions and for conducting inspections of the subframe, wall frames, roof and final inspection.
Mr Thompson agreed that the lump sum quantum of $15,000 for design work for all the issues for the house was reasonable.[513]
[513]Transcript 12-196.
I reject the builder’s primary submission that this claim should not be allowed because the design work should have been done as part of this claim. The work claimed could not have been performed as part of this proceeding. The engineer engaged to design the rectification will need to certify the design (Form 15) and that the rectification has been carried out in accordance with that design (Forms 16). The design will be complex and the engineer is entitled to be appropriately remunerated.
I also reject the builder’s submission that if structural work is required, then only an appropriate proportion of the $15,000 claimed for engineering design might be allowed. There is no reason that the lump sum engineering fee should be reduced proportionate to the amount of damages awarded for any structural work and wind related claims. The lump sum engineering fee is by reference to reasonable remuneration for an engineer’s time, not having regard to the cost of rectification.
I find that the owner is entitled to recover $18,500 plus margin being the total claimed for additional engineering design and supervision on the bases that:
(a)$15,000 is a reasonable lump sum for design; and
(b)it is reasonable for the engineer to carry out inspections as the rectification work progresses; and
(c)there is no need for a locality cost factor to be applied as the engineer will be Townsville based.

Builder’s proposal to place fill to raise finished ground level

For completeness, I find that the rectification costs should not include placing fill in the south west corner to raise the finished ground level so that the maximum eave height does not exceed 6.0m above the ground.
I make this finding as it is not necessary to do the work to ensure conformity with the contract. Placing fill would not put the owner in the position he would have been in had the builder properly performed its obligations under the contract as it would not address the fact that the building exceeds the geometric width limitations prescribed by AS 4055. Nor is it reasonable or necessary, given that the experts agreed that placing fill would not affect the wind loads on the house.

Claims made for the first time in the owner’s closing submissions

Contingency (renovate/retrofit) 20%

In his closing submissions, for the first time, the owner submitted that he should be awarded a 20% contingency amount in recognition of the complexity of the works, the duration of the proceedings and due to the order of damages sought.
I reject this claim:
(a)first, because it was not made before or at the hearing thereby denying the builder any opportunity to address it;
(b)second, because by allowing a 20% builder’s margin, a higher margin than usually allowed on new work, the experts had already recognised the complexity of the works;
(c)third, because in specific instances for which Mr Helisma included a 20% contingency to take account of potential complexity of the work and did not subsequently concede there was no basis for the claim, I have already made rulings regarding entitlement;
(d)fourth, because the duration of the proceedings is of no relevance to the amount to be awarded; and
(e)finally, because the quantum of damages sought is of no relevance at all.

Market escalation 15%

In his closing submissions, for the first time, the owner submitted that he should be awarded 15% on the award of damages due to cost escalation, in particular in recognition of increases in costs of materials and due to shortages of skilled labour.
I reject this claim:
(a)first, because it was not made before or at the hearing thereby denying the builder any opportunity to address it; and
(b)second, because I heard no evidence regarding cost escalation.

Collection of amounts awarded

I have allowed the following items for the costs of rectification:
(a)$5,500 plus a margin of 20% and a locality cost factor of 13.1% for Scott Schedule items 1.1 to 1.6;
(b)$34,599.39 plus a margin of 20% and a locality cost factor of 13.1% for Scott Schedule item 2;
(c)$6,438.10 including a margin of 20% and a locality cost factor of 13.1% for Scott Schedule item 3;
(d)$7,408 plus a margin of 20% for Scott Schedule item 4;
(e)$24,656.76 including a margin of 20%, as agreed by the experts, for Scott Schedule item 5;
(f)$22,829.18 plus a margin of 20% and a locality cost factor of 13.1% for Scott Schedule item 6;
(g)$5,000 plus a margin of 20% and a locality cost factor of 13.1% for Scott Schedule items 7 and 8;
(h)$592 including a margin of 20% and a locality cost factor of 13.1%, as agreed by the experts, for Scott Schedule item 11.2;
(i)$543 conceded for Scott Schedule item 14;
(j)$3,891.32 plus a margin of 20% and a locality cost factor of 13.1% for Scott Schedule item 16; and
(k)$1,666.73 including a margin of 20% and a locality cost factor of 13.1% for Scott Schedule item 12.3;
(l)$10,558.48 including a margin of 20% and a locality cost factor of 13.1% for Scott Schedule item 17;
(m)$18,500 plus a margin of 20% for Scott Schedule item 18.
I have not allowed a locality cost factor on items for which the quantum was based on locally sourced quotes or estimates, i.e., Scott Schedule item 4 roller door, Scott Schedule item 5 windows and Scott Schedule item 18 engineer’s fees.
I have allowed a lump sum for Scott Schedule item 11.2 footing D6 and Scott Schedule item 12.3 reinstate landscaping because the experts agreed a lump sum.
I have allowed a lump sum for Scott Schedule item 14 front door because the builder conceded that amount.
The amounts allowed total $171,136.94 including a margin of 20% and a locality cost factor of 13.1%.

GST (Scott Schedule item 20)

As is typically the case in the construction industry the quantum experts approached their costing on a GST exclusive basis. They added GST of 10% of the subtotal as item 20 of the Scott Schedule.
As the owner will have to pay GST to the rectifying builder, I find that he is entitled to recover 10% of the subtotal of his entitlement as part of his damages entitlement.
The owner is entitled to $188,250.64 including GST.

QBCC fees (Scott Schedule item 19)

During the joint expert evidence Mr Helisma and Mr Thompson agreed that the QBCC fee would only be able to be fixed once the contract price for the rectification is known.[514]
[514]Transcript 12-129.
The QBCC insurance premium fee is based on the insurable value of the work, i.e., the reasonable cost of having the work carried out. The Queensland Home Warranty Scheme Premium Table for repairs[515] sets out the applicable premium in ten-thousand-dollar increments.
[515]>
I find that the owner is entitled to recover $1,889.40, being the relevant fee for contract works valued over $213,000.
The owner is entitled to $190,140.04 including the QBCC fee.

Liquidated damages

The issues

The owner originally claimed an entitlement to liquidated damages (LDs) at a rate of $50 per day, pursuant to Clause 18 of the general conditions, due to alleged failure by the builder to bring the works to practical completion by 23 July 2018. [516]
[516]Counterclaim, [9].
In his written submissions, the owner claimed LDs of $39,200 for 784 days (the period between 6 July 2018 to 28 August 2020). The owner alleged that he terminated the contract on 28 August 2020.
During oral submissions counsel for the builder indicated that the builder would not rely on the following defences raised in its reply:
(a)it had made claims for extensions to the DfPC;
(b)the DfPC had been extended by a course of conduct;
(c)alternatively, the owner had refused to accept an extension to the DfPC in breach of his obligation to act in good faith;
(d)as a matter of law, on the basis that the conduct of the owner caused the delays;
(e)relying on the prevention principle; that time has been put at large due to the owner’s failure or refusal to approve an extension of time in circumstances where the delay had been caused by the owner.
To succeed in his claim for liquidated damages of $39,200 the owner must prove:
(a)the DfPC was 6 July 2018;
(b)the Work was not practically complete; and
(c)that he properly terminated the contract on 28 August 2020.

What was the Date for Practical Completion?

If the progress of the work was delayed by a list of nominated causes, the builder had a contractual right to claim an extension of the DfPC.[517]
[517]Clause 15.1 of the general conditions.
During oral submissions counsel for the builder conceded that the builder did not make any requests for extension of the DfPC.
During oral submissions counsel agreed that the DfPC was 7 July 2018.
Accordingly, I find that the DfPC was 7 July 2018.

Was the work practically complete?

In order to meet the contract definition of Practical Completion, the house had to be completed in compliance with, inter alia, the Plans and all statutory requirements applying to the Works. The only permissible defects or omissions were minor defects or minor omissions that would not unreasonably affect occupation.

In its written submissions the builder submitted that the house was practically complete on 5 August 2021, as evidenced by the Form 21 issued on that date. However, in oral submissions, counsel for the builder conceded that the defect rectification work undertaken by the builder as a result of the direction to rectify by the QBCC was not minor. Accordingly, it cannot be the case that the work was practically complete on 5 August 2021.

When was the contract terminated?

During oral submissions counsel agreed that the contract was terminated on 28 August 2020.

Entitlement

The owner’s entitlement to LDs runs for each day after the DfPC until the earlier of the Date of Practical Completion or the day the contract was terminated pursuant to general condition 18 of the contract. The owner is entitled to LDs of $50 per day from 7 July 2018 to 28 August 2020, 783 days, i.e., $39,150. However, this amount must be reduced by $7,100 which the owner withheld from his payment of the final invoice. Accordingly, I find the builder owes the owner liquidated damages of $32,050.

Rent

In his submissions, for the first time in the proceedings, the owner made a claim for rent in the vicinity of $550 - $620 per week from 28 August 2020 (when his entitlement to liquidated damages ceased) to ‘the date of settlement’.
The owner did not provide any legal basis for this claim. It was not made at trial, so the builder has not had an opportunity to address it.
I reject this claim.

Interest

Relevant legislation

Section 77(3)(c) of the QBCC Act gives the tribunal power to:
award damages, and interest on the damages at the rate, and calculated in the way, prescribed under a regulation.
Section 54 of the Queensland Building and Construction Regulation 2018 (Qld) (QBCC Regulation) provides:
Interest—Act, s 77
(1) For section 77(3)(c) of the Act, interest is payable on the amount of damages awarded—
(a) if the parties have entered into a contract—at the rate provided under the contract; or
(b) at the rate agreed between the parties; or
(c) otherwise—at the rate of 10%.
(2) The interest is payable on and from the day after the day the amount became payable until and including the day the amount is paid.

Finding

The contract does not provide for the builder to pay the owner interest on outstanding amounts. There was no evidence that the parties had agreed a rate. Accordingly, the owner is entitled to interest at the rate of 10% from the date of this decision until the date of payment.

Costs

Section 100 of the Queensland Civil and Administrative Tribunal Act 2009 (Qld) (QCAT Act) provides that, subject to an enabling Act, each party must bear its own costs of the proceedings. The QBCC Act is the relevant enabling Act for these proceedings. Section 77(h) of the QBCC Act confers specific jurisdiction on this tribunal to award costs in building disputes.
Subject to any further submissions that might be made regarding offers of settlement, if any, my intention is to follow the usual rule and order the unsuccessful builder to pay the costs of the successful owner.
I reserve my decision on costs to enable the parties to provide written submissions regarding the circumstances that I should take into account when making an order as to costs.

Orders

The builder must pay the owner:
(a)damages of $190,140; and
(b)liquidated damages of $32,050; and
(c)interest at the rate of 10% from the date of this decision until the date of payment.
Any application for costs must be made by filing in the tribunal two (2) copies and providing one (1) copy to the other party of any submissions and evidence to be relied upon within 14 days of the date of this decision.
If any application for costs is made, then the other party must file in the tribunal two (2) copies and provide one (1) copy to the applying party of any submissions and evidence in response to be relied upon within 28 days of the date of this decision.
The application for costs will be determined on the papers and without an oral hearing.

CITATION:	Gedoun Constructions Pty Ltd v Agius [2022] QCAT 446
PARTIES:	GEDOUN CONSTRUCTIONS PTY LTD
(applicant)
v
MARK ELLIOT AGIUS
(respondent)
APPLICATION NO:	BDL308-18
MATTER TYPE:	Building matters
DELIVERED ON:	14 February 2022
HEARING DATES:	24 August 2020 25 August 2020 26 August 2020 27 August 2020 8 September 2020 15 September 2020 27 January 2021 28 January 2021 12 April 2021 13 April 2021 14 April 2021 15 April 2021 16 April 2021 19 November 2021
HEARD AT:	Brisbane
DECISION OF:	Member McVeigh
ORDERS:	1. The applicant must pay the respondent: (a) damages of $190,140; (b) liquidated damages of $32,050; and (c) interest at the rate of 10% from the date of this decision until the date of payment. 2. Any application for costs must be made by filing in the tribunal two (2) copies and providing one (1) copy to the other party of any submissions and evidence to be relied upon within 14 days of the date of this decision. 3. If any application for costs is made, then the other party must file in the tribunal two (2) copies and provide one (1) copy to the applying party of any submissions and evidence in response to be relied upon within 28 days of the date of this decision. 4. The application for costs will be determined on the papers and without an oral hearing.
CATCHWORDS:	CONTRACTS – BUILDING ENGINEERING AND RELATED CONTRACTS – THE CONTRACT GENERALLY – whether Australian Standard 4055 can be used to give a wind classification to a house if the prescribed geometric limits had been exceeded – whether Australian Standard 1684.3 can be used to derive a general wind classification to design both cladding and timber frame Bellgrove v Eldridge (1954) 90 CLR 613 followed McGrath Corporation Pty Ltd v Global Construction Management (Qld) Pty Ltd [2011] QSC 178 applied
APPEARANCES & REPRESENTATION:
Applicant:	Mr L Campbell with Ms B Vass instructed by Connolly Suthers Lawyers
Respondent:	Mr N M Cooke instructed by Becker Watt Lawyers