Microsoft Word - AJCEB Vol.2 No.1 compiled sized.doc PERFORMANCE OF DESIGN-BUILD PROJECTS IN TERMS OF COST, QUALITY AND TIME: VIEWS OF CLIENTS, ARCHITECTS AND CONTRACTORS IN SINGAPORE THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 37 PERFORMANCE OF DESIGN-BUILD PROJECTS IN TERMS OF COST, QUALITY AND TIME: VIEWS OF CLIENTS, ARCHITECTS AND CONTRACTORS IN SINGAPORE Florence Yean Yng Ling, National University of Singapore Edwin Fu Kang Leong, Shimizu Corporation, Singapore INTRODUCTION There is a growing trend towards the use of the design-build (DB) procurement system in Singapore, which may be reflect the in- herent advantages of DB. However, DB should not be viewed as a panacea for all the flaws of the traditional design-bid-build method. Moore and Dainty (2001) found that DB teams are not integrated because indi- viduals continue to work as disparate indi- viduals based on professional divisions, hierarchical relationships and non- interoperability of project participants’ cul- tures. Katsanis and Davidson (1998) found that the DB procurement system requires owners to be highly sophisticated. In addi- tion, making DB contractors solely respon- sible does not solve the fragmentation of the industry but merely transfers the problems from owners to contractors. It is therefore necessary to determine the performance levels of DB projects in terms of their time, cost and quality, so that when this procure- ment method is used the parties enter into the contract with full knowledge of what DB can and cannot achieve. The objective of this paper is to determine the performance of DB projects from the Singapore clients’, architects’ and contrac- tors’ points of views, and to compare these views. In particular, performance is dis- cussed based on projects’ time, cost and quality performance. The importance of this study is that with the project performance known, better procurement decisions can be made to give clients value for money. The comparison of views reveals how different participants in the construction industry re- gard DB arrangements. Biased views are identified and steps can then be taken to change the mindsets of people who are prejudiced towards the DB arrangement. LITERATURE REVIEW In DB projects, contractors are responsible for the design as well as construction of a project. When the contractor provides all the design, based on the owner’s brief, and subsequently undertakes construction, this is known as ‘pure DB’ (Janssens, 1991; Turner, 1995). This arrangement is also known as the ‘traditional DB form’ (Akin- toye, 1994; Bennett et al., 1996), ‘true DB’ (Caunce, 1995) and ‘complete DB’ (Turner, 1995). It also includes package deal and turnkey arrangements. This traditional DB form accounts for 20% of all DB work in the UK (Bennett et al., 1996). The main hybrids of DB are ‘develop and construct’ and ‘novated DB’. In develop and construct, the owner signs a contract with its architects and engineers to produce the preliminary design (Chan, 2000). After the contract is awarded the contractor selects and appoints its own consultants to develop the design. They are responsible for ensur- ing structural sufficiency, method of construction and other special requirements. In this arrangement the owner’s consultants are responsible for the documents they pre- pare and contractors are responsible for technical efficacy, price and schedule (CIOB, 1988). Novated DB is also known as ‘consultant- switch’ (Pain and Bennett, 1988: 312). Novated DB has two distinct stages, the pre- novation stage which is similar to the de- sign-bid-build system, and post novation stage. In the pre-novation stage the con- sultants engaged by the owner may develop 30% to 80% of the design (Chan and Lam, 1995). At the post novation stage contractors must employ these same consultants who had carried out the preliminary design un- der the owner. Several studies on DB project performance have been undertaken. In the UK, owners have above average satisfaction with DB projects in terms of cost, time and quality performance (Ndekugri and Turner, 1994). In a later study it was shown that DB pro- jects have greater time and cost certainty, better value for money and are 50% more FLORENCE YEAN YNG LING AND EDWIN FU KANG LEONG 38 THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 likely to finish on time and be delivered on the agreed budget compared to design-bid- build projects (Bennett et al.,1996). In a USA study, Konchar and Sanvido (1998) found that quality, cost and time performance of DB projects are generally better than those of design-bid-build projects. Chan et al. (2001) suggested that the overall success of DB projects should be based on the projects’ quality, time and cost perform- ance. Following this idea the sections below review the specific performance of DB pro- jects in terms of quality, time and cost. Quality Walker (1995) noted that in the majority of cases it is not the procurement route that gives poor quality but the quality of the cli- ent’s brief — whether DB is able to deliver a quality project, depends to a great extent on the quality and clarity of the client’s brief (Akintoye, 1994). Murray (1995) agrees, stat- ing that if the final version of the brief does not sensitively and comprehensively reflect and fulfil client aspirations, then the end result will be a dissatisfied client and cer- tainly an unsatisfactory building. Hashim (1996) believes that the DB client’s brief must be clear and comprehensive and contain not only the aesthetic, technical and performance criteria for the project, but also, equally importantly, his primary and secondary objectives in terms of functional quality, time and cost. The concept of quality is very subjective and can be divided into four separate aspects (Pain and Bennett,1988): functional quality, architectural quality, technical quality and workmanship quality. Functional quality Pain and Bennett’s (1988) study to assess the functional quality of various types of construction works revealed that projects procured under DB met their objectives generally better than the conventional ap- proach would have been expected to do. Napier and Freiburg’s (1990) study showed that functional quality of DB projects, which can be represented by conformance to cli- ent’s expectations, was above average ex- pectations and overall owner satisfaction was also above average. Architectural quality There is a school of thought, the “garden shed” school, that considers DB suitable only for very simple structures such as gar- den sheds (Ndekugri and Turner, 1994), and “the method seem[s] appropriate only for cheap and cheerful buildings” (Walker, 1995). Ndekugri and Church (1996) also noted that aesthetics is seldom considered in the evaluation of tenders for DB projects with costs as main priority. A survey of ar- chitects by Akintoye and Fitzgerald (1995) also showed that aesthetic quality is gener- ally sacrificed in DB. However, Pain and Bennett (1988) inter- viewed contractors, clients and independent architects and found that majority of the respondents felt that projects under DB ar- rangements have similar aesthetic quality as compared to those procured using the traditional methods. A few respondents even felt that DB projects gave better aesthetic quality. Technical quality Pain and Bennett (1988) found that majority of the respondents thought that DB pro- duced buildings of similar technical quality in terms of materials, components, fittings and finishes as compared to the traditional approach. In fact, in certain situations, the results were thought to be even better. This is partly due to the establishment of a single point of responsibility resulting in an imme- diate reduction in the number of interfaces with whom the client comes in contact (Murray, 1995). With contractors’ early in- volvement, the DB method not only im- proves communication but also provides the opportunity to overlap the design and con- struction phases and to incorporate the concept of buildability into the design (Rowlinson, 1987). Workmanship quality In Pain and Bennett’s (1988) study it was established that the workmanship quality of DB projects is generally the same as the traditional method would have produced. In absolute terms, many of the respondents felt that workmanship quality was satisfactory. One of the reasons could be that of single point of responsibility as mentioned before whereby the contractor is solely responsible for design, workmanship and materials. An- other reason is that DB projects are more buildable. Rowlinson (1987) feels that the quality of construction is improved in DB as the architect is expected to seek buildable solutions, thereby enhancing ease of PERFORMANCE OF DESIGN-BUILD PROJECTS IN TERMS OF COST, QUALITY AND TIME: VIEWS OF CLIENTS, ARCHITECTS AND CONTRACTORS IN SINGAPORE THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 39 construction. The involvement of contrac- tors in the planning and design stages re- duces construction problems during the execution stage and they are thus able to propose highly buildable design and con- struction systems with which they are famil- iar (Ling, 1995). Time An attractive feature of DB projects as com- pared to those using the traditional pro- curement method is that of shorter time duration. Timely completion is also of vital importance in the success of the project. Shorter project duration In a survey by Songer and Molenaar (1996) to assess public and private sector attitudes towards DB and to gain an insight into owner design-build selection factors, it was concluded that shortening the duration of construction was the most important reason why owners choose the DB arrangement. The majority of the architect respondents in Ndekugri and Turner’s (1994) survey agreed that DB is generally faster than the tradi- tional arrangement. In a Hong Kong hospital project, DB was chosen specifically because the client had a tight schedule (Chan, 2000). In a survey carried out in the USA which compared different project delivery systems, DB projects were found to be at least 12% faster than the traditional design-bid-build projects and 7% faster than construction management projects (Konchar and San- vido, 1998). There are several reasons for these shorter times. Time saving in the overall project du- ration is possible by overlapping the design and construction process (Akintoye and Fitzgerald, 1995) as the DB arrangement permits the contractor to commence con- struction before the complete set of design is completed. Furthermore, Ndekugri and Turner (1994) attributed the shorter duration to contractor’s superior knowledge of the state of the industry in terms of lead times of key items of materials and components, and so arrange his/her affairs to minimise delay in their procurement. Ling (1995) fur- ther commented that the DB contractor, being responsible for both design and con- struction, can recommend the use of highly buildable designs coupled with construction systems familiar to the contractor, resulting in time-savings. Completion on time Pain and Bennett (1988) found that half of the DB projects finished on time, with one finishing six weeks early. In a survey of UK contractor’s views, Akintoye (1994) found that 54% of the contractors felt that DB pro- jects could finish on time. A survey by Mole- naar et al. (1999) of USA public sector owners found that schedule performance was excellent under DB arrangements — 77% of the DB projects were within 2% or better of the schedule established when the builder was hired. This was extremely im- pressive considering that 73% of DB con- tractors are hired with 25% or less of the design completed. Cost Previous studies are not in complete agreement on DB projects’ performance relating to cost, with some saying that DB projects are cheaper, others saying they are more expensive or the same as design-bid- build projects. A survey by Songer and Molenaar (1996) re- vealed that reduction in cost is the second most important reason for clients to select DB. In another survey by Akintoye and Fitz- gerald (1995), the results indicated that 53% of the architects claimed that DB could achieve savings in construction cost of be- tween 1% and 15%. This survey revealed very similar results compared to a previous one on contractors (Akintoye, 1994), where 62% of the contractors believed that up to 20% of costs can be saved by using DB. DB contractors are expected to involve experi- enced sub-contractors and suppliers to help architects produce designs which econo- mise on materials used and adopt methods that they are experienced in. On the other hand Ernzen and Schexnayder (2000) found that DB projects are more risky, and the average profit margin is 3.5% greater than that for non-DB work. Pain and Bennett (1988) concluded from their case studies that the cost of DB pro- jects may be the same as traditional design- bid-build projects. Turner (1995), in a com- parison of performance between different procurement methods, suggested that there was no evidence to indicate any differences in the prices tendered under either DB or traditional methods. Rowlinson (1987) commented that a lot of resources are committed to prepare a DB FLORENCE YEAN YNG LING AND EDWIN FU KANG LEONG 40 THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 tender and the risks of not being awarded the contract are usually high. Ling (1995) highlighted that tender costs could be as much as 10 times more than those under the traditional arrangement. Following that, Ndekugri and Church (1996) stated that the cost of abortive tenders would ultimately be borne by owners of future projects and soci- ety at large. In view of such wastage of re- sources, the Code of Procedure for Selective Tendering for DB (NJCC, 1985) recommends there be a maximum of four tenderers as a way of minimising the high costs of abortive DB tendering. Several studies in the UK have also shown that DB projects are more likely to be deliv- ered to budget (Chappell, 1991; Akintoye and Fitzgerald, 1995). In a survey of 50 owners in the UK, 40% said that DB is useful when a guaranteed price is crucial for the project (Chevin, 1993). Bennett et al.’s (1996) study, also in the UK, showed that 60% of owners feel that it is important to have a guaranteed maximum price, which can be achieved if the owner’s requirements are detailed. Molenaar et al.’s (1999) study in the USA on DB project performance revealed that cost performance was excellent with 59% of the DB projects within 2% of the budget estab- lished when the DB contractor was hired. The review above shows that DB is generally advantageous and performs well in the USA and the UK, however before Singapore adopts DB with greater intensity, it is neces- sary to study how DB projects perform in Singapore. METHODOLOGY In order to seek Singapore contractors’, ar- chitects’ and clients’ opinions and percep- tions of DB, a questionnaire was formulated based on the issues uncovered in the litera- ture review. In the questionnaire the first set of statements relates to quality of DB pro- jects, the second set of statements pertains to the time performance of DB projects while the third set was designed to deter- mine what respondents felt about the cost aspect of DB projects. Respondents were asked to state their level of agreement or disagreement with the issues raised on a five-point Likert scale, where 1 = strongly disagree, 2 = disagree, 3 = neutral, 4 = agree and 5 = strongly agree. Respondents were also asked demographic questions in the second part of the questionnaire. After the questionnaires were prepared, copies were sent out to contractors, clients and architects who are based in Singapore. Each questionnaire was accompanied by a cover letter indicating the objectives of the research and attached with a self- addressed and stamped envelope. The re- sponses were returned within a month of mailing. Survey forms were sent to 100 randomly selected architects listed in the Singapore Institute of Architects’ Member Directory. Another 100 questionnaires were sent to clients — this comprised: all the 40 public sector clients listed in the Singapore Gov- ernment Telephone Directory, and 60 ran- domly selected private clients listed in the Singapore Real Estate Developers Associa- tion directory. Only large contractors were surveyed because it was felt that they would have the resources to undertake DB pro- jects. There are 155 large building and civil engineering contractors (paid up capital above US$1 million each) registered with the Building and Construction Authority (BCA) and all of them were selected for this study. Random sampling of architects and private sector clients was done because it would have been too time consuming and expen- sive to survey the whole population. Random sampling was done by using a table of ran- dom numbers to pick the required number of samples. In hindsight it would have been more appropriate to increase the sample sizes for these two groups because the re- sponse rates were low. Because of the manageable population sizes all public sector clients and large contractors were surveyed. RESULTS Usable responses were received from 40 contractors, 15 architects and 15 clients. This represented response rates of 26%, 15% and 15%, which is considered to be adequate for a study of this nature. Responses from one public sector architect and 14 private architects were received with 93% of the architect respondents having practised in the construction industry for more than 10 years. The architects have been involved in public sector DB projects, private sector ‘pure’ DB projects and novated DB projects. A small number have PERFORMANCE OF DESIGN-BUILD PROJECTS IN TERMS OF COST, QUALITY AND TIME: VIEWS OF CLIENTS, ARCHITECTS AND CONTRACTORS IN SINGAPORE THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 41 also undertaken develop and construct projects. There were nine and six usable responses from private and public sector clients re- spectively — 93% of the client respondents have practised in the construction industry for more than 10 years and have been involved in public and private sectors DB projects. Of the 40 building and civil engineering con- tractors 33 (83%) had practised in the con- struction industry for more than 10 years — 90% of the respondents had handled DB projects in the past. The demographic characteristics of the re- spondents indicate that they are very experi- enced people in the construction industry. A large majority of them also have experience in DB projects, therefore their views on DB should be noteworthy. Mean ratings for all the statements relating to DB performance were calculated for each of the categories of respondents (see Table 1). These mean ratings are merely those of the sample. It is therefore necessary to find out whether the population would agree with these DB performance attributes, using Student’s t-test. This statistical test is ade- quate for this type of evaluation because it can deal with situations in which the sample size is not large (n=15 for architects and clients) and a standard normal distribution may not exist (Newbold, 1991). For each performance attribute, the null hypothesis that the attribute did not receive agreement amongst the population and the alternative hypothesis that the attribute was agreeable are set out below. To test the null hypothesis Ho: µ ≤ µo against the alternative hypothesis H1: µ > µo, where µ is the popula- tion mean. µo is the critical rating above which the attribute was considered agree- able by the population. In this study, µo was fixed at 3 because, by the definition given in the rating scale, ratings above 3 (i.e. 4 and 5) represented ‘agree’ and ‘strongly agree’. The significance level was set at 0.05. When the calculated significance (“sig.” in Table 1), p < 0.05, it can be concluded that the population agrees with the statement at a 95% confidence interval. The results of the statistical tests (see Table 1) show that contractors agree with 23 of the 30 DB performance attributes. Clients agree with 18 of these statements, while architects agree to only 17 of these statements. In many instances the three groups of re- spondents did not have the same level of agreement relating to a performance attrib- ute of DB. DISCUSSION The discussion in this section is based on the statistical results in Table 1. Quality performance Table 1 shows that contractors and clients felt that DB projects perform well in terms of functional (H1), architectural (H2) and technical quality (H3). Clients and contrac- tors did not agree that contractor-led DB projects concentrate on costs and buildabil- ity at the expense of aesthetics (H9) and quality (H10). This is consistent with UK and USA studies. In the UK, Bennett et al.’s (1996) study revealed that DB performs con- sistently better in meeting quality standards in complex or innovative buildings rather than simple and standard traditional build- ings. Moreover, DB projects deliver more consistent aesthetic quality than tradition- ally procured buildings, and score margin- ally higher in terms of aesthetic quality. Konchar and Sanvido’s (1998) USA study showed that quality of DB projects is higher than design-bid-build projects. Clients and architects do not agree that workmanship quality (H4) of DB projects are good, and that DB procurement maximises overall client satisfaction (H7). Neither do they agree that DB projects are aesthetically pleasing (H5). However, they felt that archi- tect-led DB would ensure quality and aes- thetics of projects (H11). Contractors disagreed with this, as it may mean that the arrangement is not much different from de- sign-bid-build, which carries with it inherent disadvantages such as low buildability and fragmentation of design and construction. All the respondents felt that the administra- tive burden of DB projects are not lower than traditional design-bid-build projects (H6). They also felt that when the schematic design is developed to an advanced stage before tendering, quality of DB project will be good (H8). Clients may determine the cost of quality of the DB projects using the methodology developed by Hall and Tomkins (2001). FLORENCE YEAN YNG LING AND EDWIN FU KANG LEONG 42 THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 Table 1: Statistical results of architects, clients and contractors’ ratings No. DB performance statements Architect Client Contractor Mean t value Sig. Mean t value Sig. Mean t value Sig. H1 Functional quality of DB projects satisfies client’s requirement. 3.333 1.160 0.133 3.733 4.036 0.001 4.050 8.483 0.000 H2 Architectural quality of DB projects meets client’s expectation. 3.000 0.000 0.500 3.467 1.825 0.045 3.875 7.306 0.000 H3 Technical quality of DB projects satisfies client’s requirements. 3.200 0.823 0.212 3.867 5.245 0.000 4.100 11.000 0.000 H4 Workmanship quality of DB projects is good. 3.133 0.564 0.291 3.200 0.899 0.192 3.825 8.204 0.000 H5 DB projects are aesthetically pleasing. 2.800 -0.676 0.745 3.267 1.293 0.109 3.675 4.970 0.000 H6 Administrative burden in DB projects is lower. 2.867 -0.397 0.349 3.467 1.606 0.066 3.000 0.000 0.500 H7 Usage of DB procurement maximises overall client’s satisfaction. 3.067 0.211 0.418 3.400 1.572 0.069 3.725 5.619 0.000 H8 When schematic design is developed to an advanced stage before tendering, quality of DB project is good. 3.600 2.358 0.017 3.667 3.162 0.004 3.725 5.619 0.000 H9 Contractor-led DB projects concentrate on costs and buildability at the expense of aesthetics. 3.800 3.055 0.005 3.333 1.099 0.150 2.675 -1.801 0.961 H10 Contractor-led DB projects concentrate on costs and buildability at the expense of quality. 3.800 3.055 0.005 3.333 1.099 0.150 2.300 -3.749 1.000 H11 Architect-led DB projects would ensure quality and aesthetics of projects. 3.733 2.048 0.030 3.533 2.086 0.028 3.100 0.561 0.289 H12 Usage of DB reduces physical construction time. 3.533 1.835 0.044 4.067 4.298 0.001 4.075 7.654 0.000 H13 Overlap of design and construction phases in DB reduces overall project time. 3.533 2.477 0.014 4.267 6.971 0.000 4.275 9.521 0.000 H14 Response time to design changes is faster in DB projects. 3.400 1.702 0.055 3.600 2.806 0.007 4.375 12.338 0.000 H15 Early involvement of contractor in DB allows his expertise in buildability to be incorporated for time and cost savings. 3.600 3.154 0.004 4.600 12.220 0.000 4.575 15.662 0.000 H16 Contractor's knowledge of lead times of key items and components allow materials and equipment to be procured faster in DB projects. 3.733 3.556 0.002 4.200 8.290 0.000 4.125 9.394 0.000 H17 High degree of consultation, co-operation and good information flow ensures that design discrepancies are resolved faster in DB projects. 3.533 2.779 0.008 4.000 4.583 0.000 4.275 10.743 0.000 H18 Usage of innovative construction methods reduces construction time in DB projects. 3.400 1.871 0.041 3.733 4.036 0.001 4.175 9.945 0.000 H19 DB contractors are willing to start physical construction works with limited design information. 3.333 1.435 0.087 3.333 1.234 0.119 3.700 4.462 0.000 H20 The overall pre-contract period is shortened in DB as compared to the traditional design- bid-build method. 3.600 2.806 0.007 3.467 1.284 0.110 3.700 4.857 0.000 H21 In DB projects, detailed working drawings are not necessary as design can be developed as construction is going on. 2.867 -0.381 0.646 3.133 0.459 0.327 3.375 1.922 0.031 H22 Risk of costs exceeding budget is minimal in DB projects. 2.867 -0.397 0.651 3.267 1.000 0.167 3.550 4.113 0.000 H23 DB contractors make use of value engineering to reduce costs without reducing quality. 3.467 2.168 0.024 3.800 4.000 0.001 4.050 9.297 0.000 H24 DB contractors make use of value engineering to increase quality without increasing costs. 3.467 2.168 0.024 3.800 4.000 0.001 3.900 8.473 0.000 H25 Contractors tend to reduce professional fees in DB projects. 4.067 4.000 0.001 3.400 1.702 0.056 3.150 1.183 0.122 H26 DB contractors pursue cheaper design solutions all the time. 4.067 5.172 0.000 3.600 2.201 0.023 3.125 0.842 0.203 H27 DB contractors use standardised components. 3.867 4.516 0.000 3.467 2.432 0.015 3.475 3.427 0.001 H28 Usage of DB procurement route provides clients with early knowledge of the maximum project cost. 3.600 3.154 0.004 3.733 3.214 0.003 3.775 5.894 0.000 H29 DB contractual arrangement leads to fewer disputes and claims. 3.267 0.939 0.182 3.600 2.553 0.012 3.775 5.176 0.000 H30 There is a reduction in the usage of architect and engineers’ services by DB contractors. 2.933 -0.222 0.587 3.000 0.000 0.500 2.850 -1.183 0.122 PERFORMANCE OF DESIGN-BUILD PROJECTS IN TERMS OF COST, QUALITY AND TIME: VIEWS OF CLIENTS, ARCHITECTS AND CONTRACTORS IN SINGAPORE THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 43 Time performance With regard to time performance, Table 1 results show that all the three groups of respondents agree that the usage of DB re- duces overall project development time (H13) and physical construction time (H12). This is consistent with Bennett et al.’s (1996) UK study which showed that DB projects are 12% faster in construction speed compared to design-bid-build projects, with total deliv- ery (design and construction) speed being 30% faster. It is also consistent with Kon- char and Sanvido’s (1998) finding that deliv- ery speed and construction speed of DB projects in USA are faster than design-bid- build projects. Tam (2000) also reported that construction time has been shortened because of the use of DB in a Hong Kong project. The associated reasons for the lesser time to complete the project, which are agreed by the three groups of respondents are: contractors’ early involvement allows them to incorporate buildability (H15) contractors’ knowledge of lead times of key items and components allow materials and equipment to be procured faster (H16) high degree of consultation, co-operation and good information flow ensures that de- sign discrepancies are resolved faster (H17) use of innovative construction methods (H18). The findings are consistent with Chan et al.’s (2001) Hong Kong study, which estab- lished that contractors’ competencies con- tribute to good time performance. Clients and contractors agreed on the issue of a reduction in response time because of the use of DB(H14) — it is understandable that architects disagreed with this, as they would not want to admit that they have not re- sponded quickly enough to design changes. Another issue affecting time performance is the completeness of drawings before the commencement of construction. Contrac- tors agreed that they are willing to start physical construction work with limited de- sign information (H19). In addition, detailed working drawings are not necessary as de- sign can be developed as construction is ongoing (H21). This can be achieved by ap- plying concurrent engineering principles (Anumba and Evbuomwan, 1997), and dy- namic tracking and control methodology (Pena-Mora and Li, 2001). It should be noted that some clients prefer to have construc- tion drawings for site supervision and con- trol, and in DB projects, this may not be readily available (Tam, 2000). Clients indicated that the overall pre- contract period involving preparing of cli- ent’s brief, tender documentation, and ten- dering process, evaluation and award, is lengthened for DB projects compared to traditional projects (H20). This is in agree- ment with previous studies that found that careful preparation of client’s brief is one of the success factors for DB projects (Akin- toye, 1994). To ensure careful preparation, time and effort need to be expanded, and this would lead to longer pre-contract period. Cost performance Table 1 shows that all the three groups of respondents felt that costs of DB projects may be lower (H23). This is in concordance with Konchar and Sanvido’s (1998) finding that unit cost of DB projects are lower than those on design-bid-build projects. This is because DB contractors would have con- ducted value engineering to make their of- fers more competitive and can propose design solutions that reduce cost without reducing quality, or increase quality without increasing cost (H24). In addition, contrac- tors would use standardised components (H27). Clients and architects felt that the cost of DB projects may be lower because contractors pursue cheaper design solu- tions all the time (H26) — as expected, con- tractors deny this. Clients, architects and contractors agreed that the use of DB procurement system al- lows clients to have early knowledge of the maximum project cost (H28). Bennett et al.’s (1996) study also showed that DB projects are more likely to be completed on budget, or within 5% of the budget; 75% of DB pro- jects were completed within 5% of the budget, compared to 63% of traditional pro- jects. Tam (2000) found that DB is advanta- geous because the client can obtain a firm price for the project at the outset. Clients and architects felt that the risk of costs exceeding budget in DB projects is not minimal (H22). This contradicts Konchar and Sanvido’s (1998) finding that cost growth for DB projects is only 2.17%, while that of de- sign-bid-build projects is 4.83%. FLORENCE YEAN YNG LING AND EDWIN FU KANG LEONG 44 THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 Clients and contractors also agreed that DB contractual arrangements lead to fewer dis- putes and claims (H29). The absence of variations enables DB projects to have higher cost certainty and they are also able to proceed without the disruptions and claims associated with variations (Bennett et al., 1996). With regard to professional fees, architects felt that contractors tend to reduce profes- sional fees in DB projects (H25), but con- tractors denied this. Notwithstanding this, all the different groups of respondents felt that the services or architects and engineers are still very important in DB projects (H30). This study has several limitations. The re- sponses gathered from architects and cli- ents constitute a relatively small sample and a bigger sample would therefore give a more accurate indication of opinions. Sec- ondly, investigating the opinions of clients, architects and contractors is still not suffi- cient to draw conclusions on the perform- ance of DB projects in Singapore — a possible future study could entail the use of a more rigorous method to measure the performance of DB projects. CONCLUSION The findings suggest that while contractors rated the performance of DB projects highly in terms of quality, architects seem to give the thumbs down on DB projects’ perform- ance with regard to quality. Clients appear to have a more balanced view, as they indi- cated that functional, architectural and technical quality are acceptable. Workman- ship quality, however, still needs improvement. The finding that ‘when schematic design is developed to an advanced stage before ten- dering, quality of DB project will good’ indi- cates that the construction industry in Singapore may not be ready for pure DB as yet, but may instead be more comfortable with the develop and construct form. The findings also show that all clients, ar- chitect and contractors generally agree that DB projects can be completed in a shorter time. The main reason for this is contrac- tors’ early involvement in the project, giving them the opportunity to contribute to the design upstream of the construction proc- ess. However, the shorter development time is offset to some extent by the longer time taken by clients in the pre-contract stage. Clients, architects and contractors also agreed that DB projects cost less than tradi- tional projects because of the use of value engineering and standardised components. Even though fees payable by contractors to architects and engineers may be lower, the extent of their services is not reduced. This should reassure clients that DB projects may not be less professionally designed than traditional projects. The responses of these three major parties in a DB project are encouraging, reflecting that DB, in general, performs well. These findings indicate that DB has the potential to grow and its future seems bright. With more people recognizing its inherent benefits, the usage of DB may increase in the near future. It can be concluded from the findings that architects did not feel that DB projects have good quality, time and cost performance. As clients view DB projects’ performance fa- vourably perhaps it is time for architects to be more receptive towards DB. For contractors, being in the leadership po- sition in DB projects entails many responsi- bilities, for both design and construction. Contractors should take full advantage of the opportunity presented by DB to exercise their management abilities and to push the construction industry to achieve better performance. It is recommended that clients consider carefully the procurement method to be adopted, instead of adopting traditional de- sign-bid-build as a matter of course. With the many advantages of DB identified in this paper, clients are urged to seriously con- sider DB as a viable procurement system. REFERENCES Akintoye, A. (1994) Design and build: a sur- vey of construction contractors' views. Con- struction Management and Economics, 12, 155–163. Akintoye, A. and Fitzgerald, E. (1995) Design and build: a survey of architects’ views. En- gineering, Construction and Architectural Management, 2 (1), 27–44. Anumba, C.J. and Evbuomwan, N.F.O. (1997) Concurrent engineering in design-build pro- jects. Construction Management and Eco- nomics, 15, 271–281. Bennett, J., Pothecary, E. and Robinson, G. (1996) Designing and building a world-class PERFORMANCE OF DESIGN-BUILD PROJECTS IN TERMS OF COST, QUALITY AND TIME: VIEWS OF CLIENTS, ARCHITECTS AND CONTRACTORS IN SINGAPORE THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 45 industry. Centre for Strategic Studies in Construction, Reading. Caunce, J. (1995) Hybrid pretenders threaten D&B image. Construction Man- ager, 1 (1), 21. Chan, A.P.C. and Lam, P.T. (1995) Novation contract: an innovative variation to design- build. In: Proceedings of the First Interna- tional Congress on Construction: Design and Build Projects — International Experi- ences, 197–203. National University of Sin- gapore, Singapore. Chan, A.P.C. (2000) Evaluation of enhanced design and build system — a case study of a hospital project. Construction Management and Economics, 18, 863–871. Chan, A.P.C., Ho, D.C.K. and Tam, C.M. (2001) Design and build project success fac- tors: multivariate analysis. Journal of Con- struction Engineering and Management, ASCE, 127, 93–100. Chappell, D. (1991) Which form of building contract. Architecture Design and Technol- ogy Press, London. Chartered Institute of Building (1988) Code of estimating practice supplement number two: design and build, Supplement 2. CIOB, London. Chevin, D. (1993) Client survey: fitting the bill. Building — Design and Build Supple- ment, 30, July, 4–5. Ernzen, J.J. and Schexnayder, C. (2000) One company’s experience with design/build: labor cost risk and profit potential. Journal of Construction Engineering and Manage- ment, ASCE, 126, 10–14. Hall, M. and Tomkins, C. (2001) A cost of quality analysis of a building project: to- wards a complete methodology for design and build. Construction Management and Economics, 19, 727–740. Hashim, M. (1996) Characteristics of Design and Build from the Clients’ Perspective. In: Proceedings of the International Congress on Construction. Design and Build Projects: International Experiences, 59–62. National University of Singapore, Singapore. Janssens, D.E.L. (1991) Design-build ex- plained. Macmillan, London. Katsanis, C.J. and Davidson, C.H. (1998). Horizon 2020: Design-Build. In: Proceedings of CIB World Building Congress — construction and the environment, 2025–2032, Gävle, Sweden. Konchar, M and Sanvido, V. (1998) Compari- son of US project delivery systems. Journal of Construction Engineering and Manage- ment, 124 (6), 435–444. Ling, Y.Y. (1995) Evaluation of design and build techniques in Singapore. Focus on Property and Construction in Singapore, 6, 63–67. Molenaar, K.R., Songer, A.D. and Barash, M. (1999) Public Sector Design/Build Evolution and Performance. Journal of Management in Engineering, 15 (2), 54–62. Moore, D.R. and Dainty, A.R.J. (2001) Intra- team boundaries as inhibitors of perform- ance improvement in UK design and build projects: a call for change. Construction Management and Economics, 19, 559–562. Murray, J.P. (1995) Effective briefing: the key to project success. In Proceedings of the First International Congress on Construc- tion: Design and Build Projects — Interna- tional Experiences, 72–80. National University of Singapore, Singapore. Napier, T.R. and Freiburg, S.R. (1990) One- step and two-step facility acquisition for military construction : Project selection and implementation procedures. Technical Re- port No. p-90/23, US Army Corps of Engi- neers, Construction Engineering Research Laboratory, Champaign, Illinois. Newbold, P. (1991) Statistics for business and economics (3rd ed.) Prentice Hall, Englewood Cliffs. Ndekugri, I. and Church, R. (1996) Construc- tion procurement by the design and build approach: a survey of problems. In: Taylor, R.G. (Ed.) Proceedings of CIB W92 — pro- curement systems, North meets South: de- veloping ideas, 452–462. Department of Property Development and Construction Economics, University of Natal, Durban. Ndekugri, I. and Turner, A. (1994) Building procurement by design and build approach. Journal of Construction Engineering and Management, 120 , 243–256. NJCC (1985) Code of procedure for selective tendering for design and build. National Joint Consultative Committee, London. Pain, J. and Bennett, J. (1988) JCT with con- tractor's design form of contract: a study in FLORENCE YEAN YNG LING AND EDWIN FU KANG LEONG 46 THE AUSTRALIAN JOURNAL OF CONSTRUCTION ECONOMICS AND BUILDING VOL.2 NO.1 use. Construction Management and Eco- nomics, 6, 307–337. Pena-Mora, F. and Li, M. (2001) Dynamic planning and control methodology for de- sign/build fast-track construction projects. Journal of Construction Engineering and Management, ASCE, 127, 1–17. Rowlinson, S. (1987) Design build — its de- velopment and present status. CIOB, Ascot. Songer, A.D. and Molenaar, K.R. (1996) Se- lecting design-build: public and private sec- tor owner attitudes. Journal of Management in Engineering, 12 (6), 47–53. Tam, C.M. (2000) Design and build on a complicated redevelopment project in Hong Kong: The Happy Valley racecourse redevel- opment. International Journal of Project Management, 18, 125–129. Turner, D.F. (1995) Design and build con- tract practice (2nd ed.). Longman Scientific and Technical, Harlow. Walker, M. (1995) Changing Attitudes. New Builder, 23 June, 26–28.