Last edited 08 Oct 2018

Traditional contract - pros and cons

The 'traditional' procurement route, sometimes referred to as 'design bid build' (or 'bid build' by contractors) remains the most commonly-used method of procuring construction works.

Under this route, the client first appoints consultants to design the project in detail and then prepare tender documentation, including drawings, work schedules and bills of quantities. Contractors are then invited to submit tenders for the construction of the project, usually on a single-stage, competitive basis. The contractor is not responsible for the design, other than temporary works, although some traditional contracts do provide for the contractor to design specific parts of the works.

It is considered by some that one of the main advantages of the traditional method is the greater certainty. This is because the design is finalised before contractors are appointed, and so there is clarity about precisely what is required and how much it is likely to cost.

This is as opposed, for example, to the design and build procurement route, where the tender process begins before the design is complete. This can lead to unexpected costs or other issues as after tender, and some believe that as the design is completed by the contractor, rather than by an 'independent' design team, the quality may be lower.

The traditional procurement route does allow some flexibility post tender, through issuing instructions, variations and so on.

However, it can be slower than other forms of contracting, and as the contractor is appointed only once the design is complete. This also means the contractor is not able to help improve the buildability of the design, or to input into the packaging of the works as they develop.

There may also be cost disadvantages entailed in the traditional method, as costs may rise if a large number of changes are made to the original design. In addition, since quantities are specified in the design, the contractor has little flexibility to manage the price and provide better value.