Contractor input

Contractor input

A sense check from the contractor’s perspective


All projects benefit from tapping into a contractor’s knowledge of delivery, buildability and construction techniques before design options are closed down. But this process is often prevented by commercial rules, particularly those that govern the tender process, leading to design changes after tender award, and resulting in avoidable errors as well as unnecessary waste.

Why is it important?

The design process involves the identification and exploration of different options in order to reach the best solution. But often design teams waste time working up options that are subsequently revealed to have fundamental flaws in terms of buildability, delivery or construction.

This issue has been exacerbated by the use of computational design tools. Although digital design makes it easier to explore multiple options, it does not require the designer to establish how the design will be built before committing to a particular solution.

Moreover, fewer designers these days have sufficient experience of construction to make judgements about buildability – partly due to the wider use of design and build procurement and the fact that designers are not always novated. Because of this, time and effort may be wasted on pursuing design options that are subsequently shown to be slow, expensive or impossible to build.

However it can be very difficult to obtain contractor input at the early stage of the design process. If a contractor is appointed early through some form of ‘early contractor involvement’ then it can be difficult to ensure that the contractor’s price is competitive; and there are concerns that consulting a contractor before tender could create an unfair or uncompetitive tender process.

What are the desired outcomes and how can you achieve them?

Contractors, with their knowledge and experience of delivery, buildability and performance, should be involved in all projects at an early design stage, regardless of the form of procurement. This may involve appointing the main contractor early, to harness their knowledge of construction during the development and refinement of the design, or alternatively appointing a contractor or specialist subcontractor on a consultancy basis to assist the design team.

GIRI recommends that as a minimum the client should appoint a suitable contractor or specialist subcontractor on an informal basis with the appropriate caveats, to consult with as the design develops. The role could include reviewing the design to verify that all designers have fulfilled their duties, in particular in meeting the client’s requirements and supplying the specified level of design information. (See planning the design).

Designers’ duties as described in their scope of services should be made available to the contractor in order to allow the design to be challenged if it fails to satisfy the agreed requirements at a particular project stage. Whilst this might be controversial, over time it could help regulate the quality of designs, and hence reduce errors. (See guiding the design team).

Key goal

To ensure that concept designs are tested against delivery, buildability and construction techniques in the early stages.

Practical steps

Practical stepPurposeFurther information
Appoint a contractor on a consultancy basis to assist the design team.To ensure the team benefits from those with a detailed knowledge of construction.
Assess designs against delivery, buildability and construction considerations.To reduce the likelihood of redesigns for buildability at a later stage.