How to Choose a Design-and-Build Contractor
Design-and-build delivery — where the same organisation is responsible for both the design and the construction of a project — offers significant advantages: a single point of responsibility, better integration between design decisions and buildability, earlier cost certainty, and reduced fragmentation. But the quality of design-and-build contractors varies enormously. Here's how to assess whether a design-and-build contractor can genuinely deliver what the model promises.
What Good Design-and-Build Looks Like
In a genuine design-and-build relationship, the design and construction teams work together from the outset. Design decisions are informed by buildability, cost awareness, programme, and procurement realities. The contractor's estimating and QS function is integrated with the design development — so clients understand the commercial implications of design choices as they're made, rather than after the design is complete and the tender reveals a budget overrun.
The design-and-build contractor takes responsibility for both the design quality and the built outcome. There is no gap between "what was designed" and "what was built" — and no blame-shifting between designer and builder when something goes wrong.
Warning Signs in Design-and-Build Proposals
Design by a loosely connected third party. Some contractors claim to offer design-and-build but subcontract the design element to an independent architect with whom they have no real integration. The result can be the worst of both models — a design disconnected from construction reality, and a contractor who doesn't own the design outcome.
No cost planning alongside design development. If the contractor cannot tell you the cost implication of a design decision as it's being made, they are not providing genuine design-and-build thinking. Cost awareness should be embedded in the design conversation, not reserved for a post-design tender.
Weak technical understanding in the design conversation. A genuine design-and-build contractor can discuss structural approaches, M&E coordination, compliance, buildability, and procurement as part of the design conversation. If the "design" conversation focuses only on aesthetics and the "build" conversation focuses only on price, the integration is superficial.
Questions to Ask
Who carries out the design work — in-house, or a third-party architect? How do design and cost planning interact in your process? Can you give examples of how a design was refined to improve buildability or cost efficiency? How do you handle design changes during construction — what's the variation process? What happens if there is a conflict between the design intent and the built outcome?
RCB's Design-and-Build Approach
RCB Design & Build operates as a principal contractor with genuine design-and-build capability. We coordinate with architects, structural engineers, and specialist consultants, integrate cost planning throughout the design stage, and take responsibility for the complete project from first discussion through to delivery. Our pre-construction process is specifically designed to give clients cost certainty and scope clarity before they commit to construction.
07359 872594 | contact@rcbgroup.co.uk | www.rcbgroup.co.uk