Why put it in writing?
Most building disputes come from different expectations about what was agreed. A written contract records the job, the price and the rules for changes, so both sides know where they stand. For anything more than a small job, do not rely on a verbal agreement or a one-line quote.
What the contract should cover
- The parties: your name and the builder’s full business name and address.
- Scope of work: refer to the drawings and a written specification, including materials and finishes.
- Price: whether it is fixed or an estimate, whether VAT is included, and what is excluded (for example skips, making good, decorating).
- Payment stages: amounts linked to completed stages of work, with a sum held back until the end.
- Dates: start date, expected finish date and what happens if the work runs late.
- Changes (variations): how extra work or changes will be priced and agreed in writing before they happen.
- Permissions: who is responsible for planning, Building Regulations, party wall notices and certificates.
- Site rules: working hours, access, parking, toilet use, waste removal and tidying up.
- Insurance: the builder’s public liability and, for bigger jobs, contract works insurance.
- Guarantees and defects: how snagging and defects after completion will be dealt with.
- Disputes: how disagreements will be resolved, such as through a trade body or adjudication.
Ready-made contracts
You do not have to write a contract from scratch. The Joint Contracts Tribunal (JCT) publishes Home Owner contracts designed for homeowners in England and Wales hiring a builder for small domestic works such as extensions and alterations, with versions for when you have, or have not, appointed a consultant such as an architect. Some trade bodies also provide contracts for their members’ customers.
Your rights still apply
Whatever the contract says, the Consumer Rights Act 2015 means a trader must carry out the work with reasonable care and skill. If the contract is agreed in your home rather than at the builder’s premises, you usually have a 14-day right to cancel, and the builder must tell you about it in writing.
Before you sign
- Read every page, including the small print.
- Make sure the drawings and specification are attached or referenced.
- Check the payment stages match the work, and avoid large upfront payments.
- Keep a signed copy.
See our guide to choosing a builder, and compare local builders.
Last updated: 14 October 2026
