JCT Design and Build Contract
The Joint Contracts Tribunal (JCT) Design and Build Contract (DB) is intended for use on construction projects following the design and build procurement route. This involves appointing a main contractor to design (or complete the design) of the project and then to go on and construct it. This is as opposed to the traditional procurement route in which the client appoints consultants to design the project and then a contractor is appointed to construct it.
Design and build gives a single point of responsibility for delivering the entire project, and can help ensure good buildability, cost control and speed. Some clients however, consider it is only appropriate for simple projects, where retaining control over the design is not the main priority.
The scale and complexity of design and build projects can vary considerably, but the DB contract is generally suitable for projects where a detailed agreement is required, making provision for collaborative working, sustainability, advance payment, third party rights, bonds, collateral warranties and so on.
The 2016 edition of the contract includes the following documents:
- Design and Build contract guide (DB/G).
- Design and Build sub-contract agreement (DBSub/A).
- Design and Build sub-contract conditions (DBSub/C).
- Short form of sub-contract (ShortSub): For small-scale subcontract works that are simple and involve low risk.
- Sub-subcontract (SubSub).
- Design and Build sub-contract guide (DBSub/G).
- Design and Build contract (DB) Tracked Change Document: Highlights the changes between the DB 2011 and 2016 editions.
[edit] Related articles on Designing Buildings Wiki
- Construction contract.
- Construction management contract.
- Design and build.
- Design and build - pros and cons.
- Intermediate building contract.
- JCT.
- JCT minor works building contract.
- JCT Sub-subcontract.
- Major project construction contract.
- Management Building Contract.
- Prime cost contract.
- Standard Building Contract.
Featured articles and news
Guidance notes to prepare for April ERA changes
From the Electrical Contractors' Association Employee Relations team.
Significant changes to be seen from the new ERA in 2026 and 2027, starting on 6 April 2026.
First aid in the modern workplace with St John Ambulance.
Ireland's National Residential Retrofit Plan
Staged initiatives introduced step by step.
Solar panels, pitched roofs and risk of fire spread
60% increase in solar panel fires prompts tests and installation warnings.
Modernising heat networks with Heat interface unit
Why HIUs hold the key to efficiency upgrades.
Reflecting on the work of the CIOB Academy
Looking back on 2025 and where it's going next.
Procurement in construction: Knowledge hub
Brief, overview, key articles and over 1000 more covering procurement.
Sir John Betjeman’s love of Victorian church architecture.
Exchange for Change for UK deposit return scheme
The UK Deposit Management Organisation established to deliver Deposit Return Scheme unveils trading name.
A guide to integrating heat pumps
As the Future Homes Standard approaches Future Homes Hub publishes hints and tips for Architects and Architectural Technologists.
BSR as a standalone body; statements, key roles, context
Statements from key figures in key and changing roles.
ECA launches Welsh Election Manifesto
ECA calls on political parties at 100 day milestone to the Senedd elections.
Resident engagement as the key to successful retrofits
Retrofit is about people, not just buildings, from early starts to beyond handover.
Plastic, recycling and its symbol
Student competition winning, M.C.Esher inspired Möbius strip design symbolising continuity within a finite entity.
Do you take the lead in a circular construction economy?
Help us develop and expand this wiki as a resource for academia and industry alike.
Warm Homes Plan Workforce Taskforce
Risks of undermining UK’s energy transition due to lack of electrotechnical industry representation, says ECA.
Cost Optimal Domestic Electrification CODE
Modelling retrofits only on costs that directly impact the consumer: upfront cost of equipment, energy costs and maintenance costs.

























Comments
If the design build contractor is the actual designer and is responsible to procure the materials but not required to build. Can he change the material prices after signing the contract
What does the contract say - does it allow them to change prices? eg are fluctuations allowed?