by Dr James Pain
The term “design-and-build” is a familiar one to those involved in the building industry, but many people are not entirely clear as to exactly what design-and-build is and when it would be appropriate to use it.
The traditional contract
Under traditional contracts (JCT 80, JCT Intermediate Form, JCT Minor Works Form) the contractor has no responsibility for any aspect of the design of the building. All the design work is carried out by the client’s design team — not just the overall design in terms of planning consent, net to gross, and the overall appraisal of the scheme, but every aspect of the design, right down to specifying the hinges on each door, the adhesive with which the tiles in the toilets are stuck to the wall and the type of pipes from which the drains are made. This has been the basis of the majority of building contracts in the UK for more than 100 years.
Design-and-build
Under design-and-build contracts, in their simplest form, all the design work is carried out by the contractor’s architect and the client does not have his own architect at all. Many design-and-build projects are not of the simplest form, but for the moment let us be quite clear what the fundamentals of design-and-build are. Since earliest times, many clients have gone direct to builders to have buildings constructed, with the design agreed directly between the client and the builder, with no design consultant at all — this is design-and-build at its simplest. Much minor domestic work, such as roof conversions, kitchen extensions and new bathrooms is still done in this way. Some major projects may also follow this pattern: the client can (and sometimes does) go direct to a builder in whom he has confidence, with whom he will generally have worked before and negotiate direct. The builder will use his own design staff or, if he does not have any, he will appoint a design team himself.
These are the two extremes of traditional and design-and-build contracts, the principal effects of which are:
Priority to design with traditional contracts
Under traditional contracts, led by the consultant’s team, design is very often given a high priority. However, the time taken to get started on site is long, owing to the need to complete every aspect of the design before the deal with the contractor can be struck, and the price can be higher as the contractor cannot influence any of the design decisions even if he can see cheaper ways of doing things, and there are not infrequently disputes over delays and extra costs. This is because the contractor, under the contract, is totally reliant on the client’s design team for every aspect of the design. Contracts often start before the design is really complete; the design team — giving the design a high priority — are not always so quick as they should be in producing the information, and so the contractor’s programme is upset. Not only does this genuinely give the contractor problems but he is also often given ample opportunity for maximising any difficulties caused to him in order to mask any problems of his own.
Priority to cost and time under design-and-build
Under design-and-build contracts, speed and cost are generally given a higher priority than design because the contractor is in charge of time, cost and design. The design may, therefore, not be of the highest order and some of the detail design may be inelegant, if functional. Design-and-build contracts can get started more quickly because the contract can be entered into when substantial amounts of the design have not been completed. They can be cheaper because the contractor can decide many aspects of the design and construction and has the competitive pressures of the tender process to make him find them (but this can adversely affect design). Design-and-build contracts tend to involve fewer disputes and be finished on time, more often because the contractor cannot blame anyone but himself for the majority of problems which arise, and so will resolve them.
This is a very simple overview of the fundamental differences and pros and cons of traditional versus design-and-build contracts.
Two popular misconceptions
It is worth mentioning two popular misconceptions about design-and-build.
The first is that it involves system-building of some kind. Some design-and-build is system-building but most of it is not, and can be anything within the full range of alternative methods of building encountered under traditional contracts.
The second is that design-and-build firms always have their own design departments of architects, engineers etc. Some firms do, but many do not: they use general practice firms of architects and engineers who do such work for contractors alongside traditional work for ordinary clients. Some believe that any firm offering design-and-build which does not have its own designers is not somehow a real design-and-build contractor, but many major firms operate in this way on a substantial scale. Indeed, even firms with in-house designers will sometimes use consultants depending on the pressure of work and the nature of the project.
Design-and-build in practice
Having set out design-and-build in its simplest form, it must now be said that it is only a minority of design-and-build projects which involve the client going straight to a design-and-build contractor and having no consultants working on his behalf. Design-and-build, in its most common form, is as follows:
The client will appoint a consultant team, in the traditional way, sometimes with no intention of using design-and-build at all. At some stage in the project, for a variety of reasons — usually to do with pressures on time or money — the decision may be taken to invite design-and-build tenders.
The information for tender is then presented as tender documents (known formally as the Employer’s Requirements) and may contain very variable amounts of design, from little more than a written brief right through to a fully worked-out scheme (often with planning permission), with dimensioned plans, sections, elevations, fairly detailed specifications as to materials, finishes, equipment and plant. In the latter case the contractor will have only to prepare the actual working drawings and the constructional detail.
The correct amount and nature of information to include in the Employer’s Requirements is a matter for considerable skill and judgment on the part of the client’s professional team, depending on the circumstances of the project and the objectives of the client. In general, the greater priority the client gives to design the larger the amount of information to be established by the client’s team and included in the tender documents. The more he wants economy and speed, the less the amount of information to be included and the more scope will be left to the contractor.
The level of detail can be varied for different aspects of the scheme so that some aspects might be specified or designed in some detail and others by performance only, depending on the level of importance of each to the performance of the building in meeting the client’s requirements. For instance, the detail of the reception area could be designed fairly fully, while the plumbing and drainage might be left almost entirely to the contractor. To leave areas of the design to the contractor can save time and money and virtually eliminate the possibility of the contractor being able to claim either extra time or money in relation to those areas. It is perfectly acceptable to use design-and-build in this way, and the freedom to be able to do this is one of its great strengths. The judgment of what to include and the level of detail to go to in specifying the solution is a matter for the exercise of great care and skill by the client’s team. Design-and-build is a very flexible approach, unlike traditional contracts, and how it is used can be (and is) varied enormously from job to job.
The contract
The most widely used and accepted form of contract for design-and-build is the “JCT With Contractors Design 1981”, known as WCD or JCT 81. This is accepted generally by both consultants and contractors as a very fair and workable form of contract, and there is little reason for using any other.
The BPF system
A notable recent type of design-and-build to emerge is the BPF system, introduced in the mid-1980s. The general approach is much as set out above, with the emphasis on the thorough development of tender documents and close monitoring of the contractor’s design. A major champion of this approach is St Martins Property Corporation, who have used it extensively since its introduction. There is a version of the WCD contract for use with the BPF system.
Priority to cost and time valued by many clients
The tendency of design-and-build to place performance on time and cost above design is regarded as unacceptable by many architects. On the other hand, many clients place a higher value on being kept relatively free of the difficulties which the traditional approach so often brings than any uncertain design improvement.
It is to this that the growth of design-and-build in recent years and its continuing expansion is generally attributed. However, whether the design suffers to a noticeable or significant extent is entirely controllable by the way in which the project is managed. It is only if important aspects of the design are badly managed by the client’s team and if the contractor is both poorly selected and then poorly supervised by the client’s project manager that the design need be inadequate.
Design-and-build’s strength abused
Design-and-build is a very robust approach in that, even if managed badly by both consultants and contractor, it still seems to perform tolerably well in terms of time and cost. If, on the other hand, the traditional approach is used badly the project can easily finish months late and way over the expected cost, perhaps with a lengthy dispute over claims for contractor’s loss and expense and court cases on design failures as well. There is evidence to suggest that those who do not understand design-and-build well can abuse it and simply heap unconsidered ill-defined risks on to the process and leave the robustness of the approach to get them through it. It will generally still produce satisfactory results even so, but with considerable and unnecessary strains on both the consultants and the contractor and with poor control on the design.
Design-and-build contractors — on the bandwagon?
The quality of the contractor is of major importance to the outcome of the project and it seems very likely that contractors have highly variable levels of understanding of the process and how to manage it properly. There has inevitably been an element of “jumping on the bandwagon” by contractors, often leaving the management of the whole of the project, including the control of the design, with a contracts manager who will have no experience or understanding of design at all. The result can be a very cavalier attitude to the finer points of the building. Design-and-build is seen as attractive by some contractors because the architect can be controlled (or even kept out of a lot of the decision-making altogether) thus making it much simpler for the contractor, but perhaps to the disadvantage of the final building and the client. To understand how a contractor is likely to perform on design-and-build is not easy, and certainly requires considerable research and understanding of the subject.
Summary
Design-and-build clearly suits the priorities and objectives of many clients better than does the traditional approach. However, to work well it must be managed to the best advantage by the client’s consultants. Also the contractor must be properly skilled in design-and-build and he must understand fully the opportunities that this wider role brings. He must see that the opportunities are not only for short-term profit but for longer-term work-load by giving an excellent service to his client. Repeat business from satisfied clients is a major feature in the work-load of the more successful design-and-build contractors.
