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What a design & build contractor takes responsibility for

A design & build contractor takes the design and construction responsibilities allocated to it by the contract. The label does not mean that every approval, professional service, unknown site condition or client obligation is included automatically.

JCT's description makes the employer's requirements and the agreed design responsibility central to this arrangement. [1] [2]

Define the design responsibility

Identify the starting design and the documents the contractor must develop. Record whether the appointment includes architectural detailing, structural design, building-services design and coordination of specialist packages. JCT distinguishes a design & build contract from a contract under which the builder designs only particular parts. [2]

Some projects start with the client's own consultants. A subsequent transfer of a consultant's appointment to the contractor is known as novation; it should not be assumed merely because the procurement route changes. JCT describes novation as one possible design & build arrangement, rather than a necessary feature of every project. [1]

Separate delivery from statutory roles

The construction contract should identify the organisation managing the works and subcontractors. Separately, England's building-regulations regime allocates duties to clients, designers, contractors, principal designers and principal contractors. A contractual promise to manage the project does not make those statutory questions disappear. [3]

Under CDM 2015, the principal contractor controls and coordinates health and safety during the construction phase of a project involving more than one contractor. The principal designer has a different pre-construction coordination role. Confirm who holds each appointment instead of using “project manager” as a substitute for both. [4] [5]

Put the boundaries in writing

A useful responsibility schedule asks who obtains information, who makes the decision and who pays. Apply that approach to approvals, surveys, utility alterations, access arrangements and any work supplied directly by the client. The written scope should also identify what the client must provide before work can proceed. JCT's homeowner guidance expressly covers work, price, payment, planning responsibility and access. [6]

For example, ask whether a specialist report is included, merely coordinated, or excluded. Request a named provider and a clear answer about who pays. Record the answer beside the deliverable rather than relying on “everything included”, then ask both parties to confirm the completed schedule before appointment.

Check the handover obligation

Specify the drawings, operating information, test records and warranties to be handed over, with a responsible person and delivery stage for each. A finished room and a complete information package are different deliverables. The Association for Project Safety describes handover information as several distinct records, including operation and maintenance information and safety documentation. [7]

Use the resulting schedule to identify gaps before signing, not to infer services that the contractor has never agreed to provide.

Sources 7 references
[1]
Design and Build procurement

The Joint Contracts Tribunal · accessed 2 Oct 2026

[2]
Design and Build Contract

The Joint Contracts Tribunal · accessed 2 Oct 2026

[3]
Design and building work: meeting building requirements

Building Safety Regulator / GOV.UK · accessed 2 Oct 2026

[4]
Principal contractors: roles and responsibilities

Health and Safety Executive · accessed 2 Oct 2026

[5]
Principal designers: roles and responsibilities

Health and Safety Executive · accessed 2 Oct 2026

[6]
Home Owner Contracts

The Joint Contracts Tribunal · accessed 2 Oct 2026

[7]
Construction Handover Documentation: The Complete UK Guide

Association for Project Safety / SiteSafe · accessed 2 Oct 2026

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