Board of Professional Engineers of Queensland v Peter Knight
[2016] QCAT 493
•14 December 2016
CITATION: | Board of Professional Engineers of Queensland v Peter Knight [2016] QCAT 493 |
PARTIES: | Board of Professional Engineers of Queensland |
| v | |
| Peter Knight (Respondent) | |
APPLICATION NUMBER: | OCR160-15 |
MATTER TYPE: | Occupational regulation matters |
HEARING DATE: | 5 and 6 December 2016 |
HEARD AT: | Brisbane |
DECISION OF: | Member P Roney QC |
DELIVERED ON: | 14 December 2016 |
DELIVERED AT: | Brisbane |
ORDERS MADE: | The application is dismissed. |
CATCHWORDS: | Disciplinary proceedings against a structural engineer – Professional Engineers Act 2002; test to be applied for unprofessional conduct; where conflicting expert evidence concerning the adequacy of design; complex engineering design making requiring the exercise of judgement and design compromise to cater for conflicting criteria; Relevance of the costs to remedy failures to whether that has been unprofessional conduct. Professional Engineers Act 2002 – s 3, s 7, s 129, s 131 Adamson v Queensland Law Society Incorporated [1990] 1 QdR 498 |
APPEARANCES: | |
APPLICANT: | Ms P Morreau of Counsel instructed by Clarke Kann Lawyers for the Applicant |
RESPONDENT: | Mr A Harding of Counsel instructed by Thynne Macartney for the Respondent |
REASONS FOR DECISION
Introduction – the principal issue
Background
Relevant legal principles
The notion of “unsatisfactory professional conduct”
The pier design issue and the evidence of the experts generally
Horizontal ground strains
Drainage of the subfloor space
The use of agg drains connected to the stormwater drainage system
Cost associated with remedying defects to the affected buildings
Introduction – the principal issue
This is a disciplinary proceeding against an engineer who has more or less retired from practice. It concerns the adequacy, principally of foundations designed for a 17 building retirement accommodation facility in 2005. The proceeding was contested and there were engineers called for each side in an attempt to demonstrate the adequacy or otherwise of the relevant engineering design but also going to the question of whether the design showed a lack of adequate knowledge, skill, judgement or care in the practice of engineering having regard to what might be reasonably expected of a registered professional engineer.
A principal point of interest which the proceeding throws up concerns the proper methodology to be applied to deciding whether there has been professional misconduct in circumstances where the engineer in question contends that he sought to provide a considered engineering solution to a difficult engineering problem with conflicting elements, and whether it is enough to show in a proceeding such as this that another engineer, or perhaps a body of them would not have adopted the particular methodology adopted in that case, or would have applied a different, albeit perhaps significantly more expensive solution to that which was provided. In other words, the question is whether it is demonstrated that there is a lack of judgement or care in the practice of engineering where, although the expert engineer called for the Board asserted a multiplicity of non-compliances with what he regarded as the appropriate design methodology, there was conflicting expert evidence to the effect that the adopted solution was within the range of possible solutions a prudent engineer might have adopted.
Background
The Respondent is a registered structural engineer with in excess of 35 years of experience in that role. He operated a structural engineering firm, through his company Knight Consulting Pty Ltd from 1988. Knight Consulting formally ceased operating in 2010 and the Respondent is now transitioning to retirement.
In 2002 Knight Consulting, and the Respondent, were engaged to provide engineering services for what came to be a retirement village situated at 56A Moores Pocket Road, Moores Pocket, in an area adjacent to the Bremer River in the Ipswich district. The builder engaged Mr Knight to prepare a foundation and structural steel designs for some of the proposed buildings. Other engineers with different organisations were involved to prepare the road works, and bulk earthworks, and there is some evidence that there may have been hydraulic engineering work done as well. In consequence, the Respondent prepared 13 foundation and structural steel designs for what came to be 17 buildings comprising the village, with each building comprising multiple retiree units. This will also a recreation building. The designs were based on architectural and preliminary building application drawings prepared by “Project A Building Design and Drafting”. The proposed builder for the development which engaged the Respondent was Mark Middleton who conducted the company Qld Project Developments Pty Ltd.
The retirement village came to be constructed based upon the Respondent’s engineering design, and by which he certified on 5 January 2005. There were some adjustments made to the drawings after certification which allowed for adjustment pockets on the tops of piers supporting the buildings and the addition of some detail for sub-floor ventilation. By 2008 some damage had become evident in some of the buildings at the Tivoli Gardens Village and the Respondent inspected that damage, although he did not recommend any adjustment or repair to the floors which had been affected. In February 2011, the Building Services Authority (as it then was) engaged a consultant engineer, NJA Consulting, and it produced a report into the nature and cause of the damage in what before me came to be known as the NJA report. The author of that report was a Senior Structural Engineer, John Van de Hoef.
Essentially, the NJA report concluded, after an examination of the design, that the system design for the buildings did not comply with the “deemed to comply” requirements of the Australian Standard 2870, and insofar as it involved a design solution applying engineering considerations which were permissible under that standard, it was also unsuitable for site conditions such as those which were present in this case.
In July 2014, the QBCC issued a complaint to the Applicant Board about the Respondent’s conduct in the preparation and certification of the designs and in August 2014 the Applicant was invited to provide a submission regarding the complaint. Through his solicitors he responded in October 2014. The Board then appointed an investigator who was another member of NJA to investigate the complaint in November 2014, but that investigator was replaced in February 2015 by Mr Peter Wright of Hughes Beal and Wright Pty Ltd. Mr Wright conducted his principal inspection at the site in February 2015, and on 24 February 2015 he conducted a record of interview with Mr Knight. By August 2015 the Applicant Board had determined to propose a disciplinary proceeding against the Respondent arising out of his conduct in relation to the development and on 2 September a disciplinary application was filed. That application was substituted with an amended application filed in this Tribunal on 1 December 2016.
By the terms of the amended application, the Applicant applied for orders from the Tribunal pursuant to section 131(1) of the Professional Engineers Act 2002 (the PE Act) that a disciplinary ground is established that the Respondent behaved in a way that constituted unsatisfactory professional conduct, namely:
a)Conduct that is of a lesser standard than that which might reasonably be expected of a registered professional engineer by the public or the engineer’s professional peers;
b)Conduct that demonstrates incompetence or lack of adequate knowledge, skill, judgement or care, in the practice of engineering.
The Applicant sought that the Respondent be reprimanded and that a penalty be imposed for other relief including payment of compensation and costs.
Relevant legal principles
It is well established that proceedings of a disciplinary nature such as the present, albeit civil proceedings, with the requisite civil standard of proof applying, that required to meet the standards of the so called Briginshaw test; Briginshaw v Briginshaw [1938] 60 CLR 336; Rejfek v McElroy (1965) 112 CLR 517; Adamson v Queensland Law Society Incorporated [1990] 1 QdR 498; Re Seidler [1986] 1 QdR 486.
The Briginshaw principle so-called is understood as requiring care in cases where serious allegations have been made or a finding is likely to produce grave consequences. Importantly, Briginshaw does not alter the standard of proof, that is, on the balance of probabilities, as the High Court emphasised in its authoritative re-statement of the Briginshaw principle in Neat Holdings Pty Ltd v Karajan Holdings Pty Ltd [1992] HCA 66; (1992) 110 ALR 449 at 449–50.Briginshaw does import some flexibility to the civil standard by directing attention to the strength of the evidence required in attaining the civil standard of proof, focusing on the probative value of such evidence. Essentially, it goes to the degree of persuasion of the mind.
Thus the High Court in Neat stated at ALR 449–50 that: “the strength of the evidence necessary to establish a fact or facts on the balance of probabilities may vary according to the nature of what it is sought to prove”.
In short, the more serious the allegation, the more probative or stronger the evidence needs to be. Having said this, in Neat the High Court cautioned against generalisations about the need for ‘clear’ or ‘cogent’ evidence, even where the standard of proof was correctly understood. These were ‘likely to be unhelpful and even misleading’.
The orders which are presently sought are enlivened if I am satisfied that one of the disciplinary grounds set out in section 131 of the PE Act, but relevantly the consideration here is whether the Respondent behaved in a way that constitutes unsatisfactory professional conduct. That expression is defined by section 7 and Schedule 2 of the PE Act as including, relevantly for present purposes:
a)Conduct that is of a lesser standard that that which might be reasonably be expected of a registered professional engineer by the public or the engineer’s professional peers;
b)Conduct that demonstrates incompetence or lack of adequate knowledge, skill, judgment or care, in the practice of engineering.
There are other categories of misconduct which are defined in the schedule to the PE Act, but they are not relevant for present purposes. Indeed notwithstanding that the application focused in broad terms upon the two above mentioned categories of unprofessional conduct, in the application itself the basis on which it is contended that the Respondent’s designs were defective focused upon the fact that in relevant respects “a competent engineer, exercising proper skill, knowledge and judgment, would not have prepared or issued the designs” because they contain specific defects.
There were originally six categories of defects identified, by the conclusion of the hearing these had been reduced to four and they were as follows:
a)The piers were not suitably designed to resist or otherwise accommodate uplift forces from the sub-soil as recommended in Supplement 1 section C4, Clause (d) of Australian Standard 2870-1996 Residential Slabs and Footings and Clause 4.3.6 and Clause 4.5.4 of AS2159-1995 Piling Code - Structural Issues, or at all.
Particulars
i)The depth of seasonal influence (1.5m to 1.8m) was less than recommended in AS2870-1996 for Ipswich (2.3m);
ii)There was a failure to either isolate the top of the pier from uplift forces, or, alternatively anchor the piers sufficiently deep into the sub-soil to resist the uplift forces on the top of the piers.
b)The floor framing was not designed to provide longitudinal continuity or provided with a low friction slip layer to minimise or prevent damage to the structures from large horizontal ground strains in the event of subsidence of underground mines.
c)The sub-floor space was excavated into extremely reactive clay soil and was not provided with any form of drainage to remove water, should it enter the excavation, so as to prevent excessive reactive clay soil swelling and damage to the building as recommended in Clause B2.3(a) of AS2870-1996.
d)The area behind the perimeter walls to the basement spaces were connected to stormwater drains which could potentially back up and flood the extremely reactive sub-soil around the perimeter of the basements causing excessive reactive clay soil swelling and damage to the building.
The notion of “unsatisfactory professional conduct”
The task of determining the meaning of the expression “unsatisfactory professional conduct” of course requires a consideration of the language of that expression in its context in the PE Act, and section 7, Schedule 2. In submissions, neither party placed before me any authority which had dealt with the way in which these statutory provisions were to be applied, particularly in circumstances where there was a real conflict as between purported engineering experts about whether conduct is unprofessional in the relevant sense.
Mr James Thomas QC, when sitting on the Queensland Commercial and Consumer Tribunal, said in Board of Professional Engineers of Queensland v Manwin [2009] QCCTE 1 at [55] that the term “unsatisfactory professional conduct” under PE Act ... “is far wider in scope than earlier covers professional misconduct, “unprofessional conduct” and “malpractice” and seems to be designed to protect members of the public from incompetence and other stated shortcomings on the part of professional practitioners”. That it captures a broader category of unprofessional conduct may be inferred from the fact that by section 3 of the PE Act, its objects are:
a)To protect the public from insuring professional engineering services are provided by average to the professional engineer in a professional and competent way; and
b)To maintain public confidence in the standard of services provided by registered professional engineers; and
c)To uphold the standards of practice of registered professional engineers.
Section 4 provides that the objects are to be achieved, inter alia, by providing for the registration of engineers, and imposing obligations on persons about the practice of engineering. Section 129 of the Act provides that this Tribunal is to have regard to the Code of Practice for Registered Professional Engineers in Queensland in considering whether an engineer’s conduct constitutes unsatisfactory professional conduct.
The preamble to the Code provides that engineers “combine detailed technical and professional understanding and the wise application of that understanding”. Clause 1.3 of the Code requires that engineers “take reasonable steps to safeguard the health, welfare, and the safety of the community”.
Clause 3.1 of the Code requires that a registered professional engineer bring to the engineering task “knowledge, skill, judgement and care that are of a standard which might reasonably be expected by the public or the registered professional engineer’s professional peers. In considering the appropriate standards, registered professional engineers should have regard to industry and performance standards”. There is some authority for the view that there is a high standard expected of engineers because of the often times critical nature of the responsibilities attaching to their decisions when taken during the course of practice of their discipline because of the potentially grave and serious repercussions where there is a lack of such discipline.[1]
[1]BPEQ v Jutte [2005] QCCTE 2 at [101]-[102].
Of course, the PE Act is not prescriptive, nor does it establish a code of conduct to be applied to particular engineering problems, nor does it point the engineer to only one appropriate engineering solution. It is axiomatic that different engineers might arrive at differing, even conflicting engineering solutions to the same engineering problems even when applying appropriate knowledge, skill and judgment in the practice. Moreover, even where there are accepted Australian Standards, for example relevantly in this case, AS2870-1996 which concern the design of residential slab and footings, there is of necessity a requirement for the exercise of judgment by an engineer as to the manner and extent of its application to a particular problem and as to whether even if applied, it is an adequate or appropriate solution to a particular engineering problem.
In Manwin v Board of Professional Engineers of Queensland [2008] QDC 204, Judge McGill made a number of remarks which are relevant to the issues for considerations in the present case. First he took the view in the context of a case where an engineer was alleged to have failed to nominate the maximum permitted span for a continuous beam, that even if such was a wrong conclusion, it does:
“Not necessarily follow that this error amounted to unsatisfactory professional conduct”. In the area of negligence the mere fact that a professional person makes a mistake or is shown to have given advice which a Court is persuaded was wrong is not necessarily negligence; the question is whether it was advice which no such professional exercising reasonable care and skill would have given, which is really a different question. It seems to me that there was a separate issue here as to whether the failure to give correct advice actually amounted to unsatisfactory professional conduct in one of the ways alleged. The definition of unsatisfactory professional conduct may extend to negligence, but it does not extend to just making a mistake”.[2]
[2]At the Reasons par 18-19, and citing Brickhill v Cooke [1984] 3NSWLR 396 at 399; “Professional Liability Australia” (Second Ed 2007) page 787.
In Manwin there was an allegation as well, that the engineer had engaged in unsatisfactory professional conduct in refusing to have certified the designs in a way which the judge suggested amounted to the appellant being criticised “for being too cautious”.
Whilst expressing the view (Reasons par 24) that proving a case like that might be difficult, and that in principle an overly cautious engineer might be found to have engaged in unsatisfactory professional conduct, His Honour concluded that:
“Such a question would require rather more evidence directly specifically to those matters, and more consideration from the Tribunal, before such conclusion could be reached. It may be that a suitably qualified expert would be able to say that no reasonably competent professional engineer would have refused to certify the beam. Such evidence if it were accepted would provide a proper foundation for the finding of unsatisfactory professional conduct on this basis”.
The point to be observed about this, is that His Honour was, in my respectful view correctly, identifying that the question to be considered did not merely turn upon whether conduct by one engineer might be capable of being criticised by another in a particular case, but whether the evidence went so far as to provide a proper foundation for and finding of unsatisfactory professional conduct, having regard to what competent professional engineers do. If competent professional engineers might do different things in the same context, even if it involved a different interpretation of or application of an engineering standard, it does not follow that one or other of those engineers has engaged in unsatisfactory professional conduct.
In the course of oral submissions by Counsel for the Applicant, I was invited to examine the evidence of the two engineers who were called (apart from the Respondent himself) to speak to the adequacy of the design, and to decide which was is “correct”. When I raised with Counsel the question of what evidence there was of what the objective standards were for reasonably competent professional engineers in this context, and referred to the absence of direct evidence on this subject by the expert called for the Applicant, the response implied that the establishment of what those standards were could not conceivably require the calling of a multiplicity of engineers who would each address the question of what they might have done in those circumstances in order to form a view about what were objectively proper standards of conduct. Professional standards are the subject matter of evidence before the Courts on a regular basis. The standards are not proven by the weight of numbers of professionals who claim to adopt them, but they are not to be inferred from the expressed design preferences of a particular engineer.
One of the other issues that arose in Manwin v Board of Professional Engineers of Queensland concerned whether there was unsatisfactory professional conduct in refusing to certify a strengthened beam. McGill DCJ at [23] identified that what the engineer in that case had been asked to do was express a professional opinion, as an engineer, as to whether the particular structure was adequate. He concluded:
Whether his refusal to certify it as adequate amounted to conduct of a lesser standard than that which might reasonably be expected of a registered professional engineer, or conduct that demonstrated a lack of judgment or care in the practice of engineering, did not depend on whether another engineer disagreed with him, even if that engineer had been an experienced structural engineer, but on whether his position was one which demonstrated a lack of judgment or care, that is to say, was a position which would not have been taken by any engineer demonstrating appropriate judgment or care, or would not have been adopted by any engineer behaving in accordance with the standard reasonably to be expected of him. It is by no means clear that the respondent’s expert was even purporting to pronounce on these matters, or that he would have been properly qualified to do so in relation to an issue of structural engineering. Indeed, it seems to me that his evidence on the point was appropriately cautious.
The pier design issue and the evidence of the experts generally
The principal complaint against the Respondent that the concrete reinforced piers designed to go beneath each building and vertically into the earth for some distance were not suitably designed for the soil type and other features of the building.
On the Applicant’s case, there were two aspects of this complaint. The first was that the Respondent, it has said, adopted the incorrect seasonal influence level in determining the depth of the piers, having regard to what it is said the Australian Standard 2870-1996 required. The second aspect concerns an alleged failure to isolate the top of the pier from uplift forces or anchor the piers sufficiently deep so as to protect them, and the structure above from vertical pier movement associated with the reactivity of the subsoil. The second aspect is in part an aspect of the first because it concerns alternate methodology to constructing deeper piers, which might have dealt with the consequences of seasonal reactivity in the soil.
It was common ground that at the time the Respondent was engaged to prepare his designs, that he was made aware that there were two critical considerations which he was required to address. The first, although not in his mind necessarily the most critical, was the fact that analysis had shown that the soils on the site were reactive clay soils. The second was that the subject site was in an area in which there were old underground mine workings, and there was a potential for mine subsidence under the site.
Mr Peter Wright, the expert called for the Plaintiff and a structural and technical engineer, provided three statutory declarations, with the primary one dated 3 August 2016 exhibiting most of the historical documents, as well as his own lengthy investigative report. Mr Wright was also a joint author of a joint expert report written together with Mr Gould, who was the structural and civil engineer called in the Respondent’s case.
Apart from his role in providing the joint expert report, Mr Gould prepared two reports, the first dated 28 May 2015, and the second 11 March 2016. Both experts gave oral testimony in addition to what was contained in their reports or statements and each was cross-examined, albeit in neither case in a way which made any direct or substantial challenge to the conclusions that each of them had reached in their written material.
For the Applicant it was submitted that I should prefer the opinions expressed about the adequacy of the design elements by Mr Wright because he had “extensive apposite experience” and had, since obtaining his formal qualifications in 1976, undertaken design work in respect of small buildings, including designing footing and framing systems as well as being involved in laboratory testing of soils and the classification of sites. He has, as he swore in his oral testimony, investigated small building failures including numerous foundation failures, water penetration, foundation movement and drying of subsoils. I accept that Mr Wright was well qualified to speak about the design practices that he adopted, and perhaps those of other engineers with whom he worked and he presented as a careful and credible witness although, as I have said, cross-examination of him scarcely challenged the conclusions that he sought to reach that were in conflict with those reached by Mr Gould.
On the other hand, Mr Gould also had considerable consulting engineering experience, with a Bachelor of Engineering Degree with Honours from the University of Queensland in 1978. As with Mr Wright, he had acted as an expert witness in many Courts over time and had engineering design experience.
For the Applicant it was submitted that I should prefer the opinions of Mr Wright over those of Mr Gould because Mr Wright had been more actively involved in residential design and that Mr Gould had some experience in that regard but that it was much more dated. Both had had some professional experience in mine subsidence issues. In his oral testimony in cross-examination Mr Gould said that he had not recently been involved in residential footing design, or at least not since 2012. He had worked on an indigenous housing project across the Northern Territory where he had been involved in extremely reactive soils. He swore that before that for many years he had been involved in slab and footing design for houses, and had also been involved in mining subsidence in areas in the Ipswich district. He conceded he had not worked on a site where there were the two features, mine subsidence issues and reactive soil.
I found Mr Gould to be a careful and objective witness, who was, if anything, restrained in the way that he expressed his opinions, and overall gave the impression of being a conservative witness who was careful in the expressions of opinion he gave.
In each of his reports, Mr Gould set out the basis of the complaints which were made against the Respondent, dealt with those respects in which there was a level of judgement and expertise required to reach an engineering conclusion and expressed a view in terms of whether the design aspects which were being criticised were to a suitable standard and in respect of which appropriate skill and judgement had been applied. He was also careful to identify in a number of ways those respects in which the Respondent was forced to adopt design criteria imposed upon him by others involved in the project, to make a decision which involved some compromise in design judgement.
On the other hand, whilst Mr Wright did not in the way in which he presented at the hearing room, suggest that he was in any way partial, or advocating for the position of the Applicant, the same cannot be said of some of the statements which made their way into his reports. For example, in his report to the Applicant dated 17 March 2015, in the executive summary thereto, after expressing opinions that were within his area of expertise, he then swore the issue in asserting that the Respondent’s conduct in providing the design for the buildings was in his opinion “of a lesser standard than that which might reasonably be expected by the public and by his professional peers”. He also made the assertion that the Respondent’s conduct demonstrated “a lack of adequate knowledge, skill and judgment in the practice of engineering”.
I would ordinarily have placed no weight whatsoever upon assertions which swear the issue which I am to determine, and I have not done so here, as Counsel for both parties accept I ought not. It is, however, significant that these statements of opinion were not substantiated in the body of the report itself by identifying what the relevant Standards were, why they might be reasonably expected by professional engineers or what the basis was for the conclusion that the Respondent demonstrated a lack of adequate knowledge, skill and judgment in his practice.
One of the reasons that may be inferred drove Mr Wright to state these matters was his interpretation of things that were said to him by Mr Knight in an interview conducted by Mr Wright on 24 February 2015. Mr Wright’s first report which contained the aforementioned opinions was produced within three weeks of that interview. At page 23 of Mr Wright’s first report he said he took into account the following matters, which he said he derived from that interview:
a)That the Respondent was aware that mine subsidence could cause both vertical and lateral movement, possibly in the order of 100mm, and also that reactive clay soil movement could generate 100mm of vertical movement;
b)That the footing piers’ founding depth was selected by adding about 1 metre to the seasonal movement on the subsoil;
c)That the depth of seasonal influence was 1.5-1.8 metres and higher in Ipswich;
d)That no provision was made in the Respondent’s design drawings to drain the holes created beneath the buildings;
e)That drains behind the perimeter rat walls were intended to be connected to the stormwater drainage system and that no consideration was given to the stormwater drainage surcharging those drains and saturating the subsoils they were intended to drain;
f)That little consideration was given to uplift forces that could be exerted on the piers by swelling reactive clay subsoil;
g)That some thought was given to, and the facility designed in order to re-level the floors should ground movement cause distress and damage to the superstructure;
h)That some consideration was also given to the necessity to re-adjust external paving when the floors were re-levelled;
i)That little consideration was given to uplift on the surrounding paths and rat walls beneath the external walls of the building from swelling reactive clay subsoil;
j)That some consideration “may have been” given to potential lateral forces generated by mine subsidence early in the design phase;
k)That “little consideration” was given to the durability of the timber floor;
l)That subfloor ventilation details were included on the drawings in order to satisfy the building certifier.
The Respondent swore an affidavit dated 3 August 2016 and he was cross-examined. His explanations for why he did that which he did in the designs for the subject structure differ significantly both as to their content and their context in that affidavit and in his evidence from the conclusions which I have summarised above as having founded the opinions of Mr Wright. While some attempt was made in cross-examination of the Respondent to suggest that the differing version he had given in response to the questions in the interview was accurate, during final addresses, Counsel for the Applicant conceded that the Tribunal should act upon what the Respondent said in his affidavit and in his oral testimony, where it conflicted with what was said in the record of interview. In other words it was not being suggested that the Respondent is not telling the truth about his state of knowledge and his design intent, and what he sought to achieve in that design, in his evidence before me.
A reading of the conclusions expressed by Mr Gould, demonstrates that they more consistently adopt the interpretation of the facts described by the Respondent in the interview, rather than those expressed by Mr Knight in his testimony.
In general, I prefer the opinions of Mr Gould where they differ with those expressed by Mr Wright, although they are by no means in conflict on a wide range of issues, as the topic areas showing the areas of agreement which appear in the joint expert report reveal.
Against that background, I turn to the first issue, namely the question of whether the pier design, and their depth manifested unsatisfactory professional conduct in the relevant sense.
Both experts acknowledge that the Respondent’s design called for piers to be embedded 2 metres below the blinding layer at a minimum, and that as Mr Knight had said, some piers were imbedded to a greater depth where a different soil type was encountered during the drilling. It came to pass during the evidence-in-chief of Mr Gould that he placed a different interpretation upon where it was that the depth of influence was to be calculated, and in his case he would have included the 600mm length of the piers in the void. In other words, Mr Wright counted only the pillar depth below ground. Mr Gould counted the length above as well.
Mr Wright expressed his conclusions in terms of what he considered to be “the more appropriate design solution”, which would have been to embed the piers no less than 4.6 metres below the blinding level because the reactive clay soils were more active nearer the ground surface. Hence a pier imbedded deeper would be more resistant to the heaving of the upper layers because it was anchored in more stable soil. On the other hand Mr Wright acknowledged that in the event of mine subsidence, a deeper pier of the length he proposed may have undergone greater lateral movement than a shallower pier of 2 metres of depth. He preferred a solution with a deeper pier because, in his view, mine subsidence was a less frequent occurrence than movement from reactive clay soil changes and because in his view, the reactive clay soil movement ought to have been the dominant design consideration.
On the other hand, Mr Gould gave careful consideration also the background information and contemporaneous documentation that was available to the Respondent at the time that he was charged with conducting his design. His interpretation of that material, which I accept as more reasoned than that which founded the view of Mr Wright, is that the dominant design criteria advanced by other engineers, the mining subsidence engineer and the local authority as set out in the development approval was to consider the potential for mine subsidence. Hence, whilst he accepted that imbedding the piers to the greater depth Mr Wright referred to might have reduced movement from reactive clay soil, it would not have achieved the objective of having the piers closer to the surface to minimise the impact of mine subsidence. He identified, consistently with the unchallenged evidence of the Respondent, that the Respondent had designed the structure in a way such that there would be an ability to jack up the floor to level it. The design specified that this was to occur by including jacking points and adjustable tie down rods on the piers. Hence the engineer designed his footings in a way which contemplated, indeed required floor levels being adjusted periodically to ensure that any movement was levelled. I accept that it was an intentional design feature of this engineering solution that the floor was expected to move to some degree and would have to be adjusted from time to time as it became necessary. In his view, which I accept, the jacking system was a reasonable design solution to deal with both mine subsidence and reactive clay soil movement.
Mr Wright did not agree that allowing for the provision of jacking was an “appropriate means of managing” reactive clay soil movement issues due to the frequency of such movement”. There was criticism by the Applicant of the Respondent for failing to insert something specifically on the drawings which recognised the need for regular inspection and the necessary levelling of the floor. Whilst this criticism has some justification, I accept the unchallenged evidence of the Respondent that he described the necessity for those inspections to occur in timely meetings he had with the developer and its representatives.
There was evidence that there would have been considerable additional expense associated with constructing the piers to the depth that Mr Wright contended for, and I accept that additional costs would have been substantial. Mr Gould calculated it at an extra $400,000.00. Mr Wright did a rough calculation which brought it in at $202,000.00. I prefer Mr Gould’s evidence as to what that additional cost would have been. Had there been proper monitoring of levels by the owner the necessary adjustments ought not have involved significant expense. Mr Gould opined that if he had been doing the design himself, he would not have adopted the practice which Mr Wright suggested was “the more appropriate design solution”.
Putting all cost issues aside, and even accepting that a more appropriate design solution albeit one which involved significantly greater cost than the one the Respondent adopted, namely to have imbedded the piers at no less than 4.6 metres, I do not consider that the Applicant has discharged the onus of demonstrating that the methodology and design philosophy which the Respondent described in his evidence as having been adopted, constituted unsatisfactory professional conduct.
Horizontal ground strains
This aspect of the complaint concerned the fact that each of the 17 buildings consisted of eight separate units set in a row and that they were kept separate by firewalls to prevent the spread of fire. It was common ground that in the event of mine subsidence, there could have been resultant horizontal forces in the soil acting on the buildings and that this was a factor that needed to be taken into account in the design.
For the Applicant, via Mr Wright, it was contended that there was a lack of longitudinal restraint on the floor system to prevent the lateral movement of one or more units away from the adjoining units. In this opinion, if such a movement had occurred it could or would result in damage to the walls and roof framing and cladding. He suggested that “the design solution to this problem would have been to provide a longitudinal restraint in the form of rods or beams running the full length of the building, together with slip joints between the bearers and the concrete piers to allow the piers to move horizontally without dragging the building’s superstructure with them”.
It is to be observed that the problem which such a design solution might have existed to prevent, has not in fact occurred. There has not been lateral movement of any of the units away from adjoining units, nor any mine subsidence. Hence this is a design problem simpliciter, which has had no consequence to date.
One of the matters that Mr Wright had originally expressed a view about, was to the effect that there was no low friction slip layer provided to the pier framing interface, however it was conceded for the Applicant that such a slip layer was in fact provided by ant capping, although the Applicant continued to assert there was still insufficient longitudinal restraint on the floor system.
There was much debate between the experts as to whether some or other of the features of the building, as designed, did in fact provide for sufficient horizontal restraint in the form of edge beams, wall framing and roof structure, sufficient to resist the horizontal forces if they were mobilised. According to Mr Gould, since this was a lightweight structure, it had the ability to move across the top of the piers, and that would relieve the lateral forces. He did not consider slip joints to be necessary due to the lightweight nature of the structure. In his oral testimony, Mr Gould gave evidence, which I accept, that:
a)The Respondent’s design did provide sufficient longitudinal and latitudinal support because as a rectangular frame it was sufficiently rigid to hold it together;
b)There were firewalls between each of the units, and these provided some strength, with the floor being fixed to the bearers and the wall running down the long side of each building being continuous;
c)The nature of the buildings being lightweight timber structures was to allow for flexibility, and they were repairable in the event of any damage;
d)Being lightweight structures they had the ability to move across the top of the piers which would relieve the lateral forces.
Whilst I accept Mr Wright’s evidence that a better design detail would have been to provide additional longitudinal support, the fact that it did not do so does not lead to the conclusion that:
a)The Respondent did not specifically turn his mind to what lateral restraints were necessary and design for them accordingly; or
b)In adopting the design that he did, having regard to the considerations that he took into account, that his design evidenced unsatisfactory professional conduct in the relevant sense.
Drainage of the subfloor space
Beneath the floor space and adjacent to the piers and rat walls which surrounded each building was a 600mm void or air space below the floors. At the foot of that void was a thin concrete layer which went over the exposed soil and which was generally described as a “blinding layer”. As particularised, the complaint was that the subfloor space had been excavated into reactive clay, and that there had not been provided any form of drainage to remove water should it enter the excavation so as to prevent excessive movement of the dwelling due to the reactive clay soil, and consequent damage to the building.
Mr Wright’s conclusion, which came perilously close to swearing the issue, if it did not actually do so, was that “a prudent engineer would have designed a drainage system for the subfloor voids to avoid the risk that any water that should end up in the void space remains trapped, and then soaks through cracks in the blinding layer to the extremely reactive subsoil”.
I accept the Respondent’s evidence that he did give consideration to the manner in which these areas would drain, should they be exposed to water. A critical feature of the opinions expressed by Mr Wright in his report on this issue as appears at paragraph 3.8.4 of his report, is that the Respondent did not design drainage systems to remove free water that might enter and be trapped in the deep excavations beneath the underfloor spaces. He also insisted that no apparent consideration was given to the possibility that agg drains, or subsoil drains were designed to be connected to the stormwater drainage system and that these might cause backflow up the drains into reactive subsoil. Both of these conclusions are inconsistent with the unchallenged sworn testimony of the Respondent, that he did give consideration to this matter. I accept the Respondent’s evidence in that regard.
As Mr Gould explained, and which I accept, the void was protected from moisture entering into that area by the fact that there was a fully enclosed roof over the building, and the surrounding areas around the building had a fall away from the building so that there might be a minimum or no surface water entering the void. The rat walls around the perimeter of the building were designed to protect the void space because there was an agg drain constructed on the outside of the rat wall which ought to have taken water away. Thus there was minimal or no requirement for drainage to the void space. There is no suggestion that there has in fact been any flooding of the void spaces.
Ultimately, Mr Wright’s opinions about what should have been done to drain this area are expressed in terms of what, in his opinion, “ought to have been done”. He does not express that view by reference to what was common or usual experience by professional engineers. This is an example of criticism of a design which might have been improved, but which notwithstanding the absence of those improved features, did not evidence unsatisfactory professional conduct in failing to give consideration to the extent to which there would be prevention of water or moisture access to the void area.
The use of agg drains connected to the stormwater drainage system
The Applicant’s complaint in this regard is that the Respondent designed the use of agg drains outside the rat walls to the exterior of the building such that those agg drains were connected to the stormwater drainage. This is said to be unprofessional conduct where this design was intended to ensure groundwater from the perimeter of the building, and under the perimeter pathways, was taken away from the building and minimise the risk of it penetrating the reactive soil below the building where the footings were.
Once again, in his original report, Mr Wright’s criticism was that the Respondent gave no apparent consideration to the possibility that the agg drains connected to the stormwater drainage system could allow water to flow back up the drains and into the extremely reactive subsoil adjacent to the perimeter piers.
In his record of interview with Mr Wright, the Respondent said that the circumstances by which the design included that design detail was that it occurred at the request of the certifier. The certifier had approved the drawings and had the opportunity to review the detail which had been included by Mr Knight and the certifier had the responsibility to review the solution that he had nominated. According to Mr Gould’s evidence, which I accept, it is not unusual for a structural engineer to include requirements such as ventilation which would ordinarily be taken from architect’s drawings.
In the joint expert report, Mr Wright’s criticism of the fact that the agg drains were connected to stormwater was not referenced to any particular engineering practice or to what might be described as what might reasonably be expected of a professional engineer in relation to such issues. His opinion in criticising the drawings was referenced to the fact that stormwater drains can back up overflow during high intensity rain events and introduce a risk of soaking the reactive soil. According to Mr Gould, whose evidence I prefer, the inclusion of perimeter agg drains were a typical engineering detail intended to provide protection to the void space, and that the connection of an agg pipe to the stormwater drain was “normal practice”, particularly as here where the stormwater drain to the north with reasonable fall. I accept his evidence that likely backup from a stormwater drain was an insignificant issue and that even if there was a backing up event, that as designed, the water would eventually drain away at the conclusion of the event without negative consequences. The Applicant has not established that to have included such a detail was unprofessional conduct.
Cost associated with remedying defects to the affected buildings
In the expert reports, and in the oral testimony before me, there was a body of conflicting evidence about what the likely cost would be to remedy what were said to be consequences of the Respondent’s alleged unsatisfactory professional conduct. Estimates ranged from a figure identified by Mr Wright as $317,000.00 just in respect of the five of the 17 buildings which had hitherto been inspected, but extended to an estimated cost of $3.5 to $4 million to demolish and reconstruct those five buildings. Inferentially, if all 17 were to be demolished and reconstructed, one would be looking at a very large sum indeed.
I expressed the view in the course of the hearing that I struggled to see that the issue of whether those costs were involved or not, was a relevant consideration to determining whether there had been unsatisfactory professional conduct. I was assured by Counsel for the Applicant that I could usefully have regard to those sums in determining whether there had been unsatisfactory professional conduct. Notwithstanding that assurance, in a case such as this where the Respondent is not alleged to have failed to give consideration to relevant issues in the design process, but the resultant design is criticised, it is difficult to see what these cost estimates do to assist a resolution of the issues before me. It is common ground that the Respondent intended the levels of these buildings to be monitored to ensure that they were re-levelled so that there was no resultant damage. The fact that the developer or operator of the site did not do this, leading to an accumulation of problems, does not mean that these costs were in some way a foreseeable consequence of the design that he developed.
Moreover, it has been well accepted, albeit in an environment in which Courts were considering whether a solicitor had been guilty of professional misconduct, that in considering the gravity of the misconduct that the fact that the client, in the ultimate event, suffered no loss is of little, if any, relevance.[3] As the Court in Moulton said:
“If the acts or omissions of a solicitor constitute professional misconduct, they do so at the time when they occur. Their character is not changed by the fact that subsequently a loss, or no loss is sustained. The presence or absence of loss may throw light on the propriety of action taken to ensure the adequacy of a security for a loan, but that propriety is to be found primarily in the steps taken at the time the loan is made, and not by what happens some years later.”
[3]Law Society of New South Wales v Moulton [1981] 2NSWLR 736 at [740].
The Court made reference to the fact that these propositions were not new law and had been stated much earlier in the decision in Law Society of New South Wales v Harvey [1976] 2 NSWLR 154, although having read that discussion it is less clear on the point that what was said in Moulton.
It follows from the findings that I have made that the application is dismissed, and I so order.
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