Builders · Contracts and scope

Contracts, scope and variations

A clear contract protects both sides. For a builder, it is also the main evidence if a customer later disputes what was agreed or refuses to pay.

Information, not legal advice. This guide explains official rules in plain words for England, with links to the sources. Rules change and every job is different, so check the source or get advice for your situation. Last checked 24 October 2026.

Why write it down

A contract can be made by talking, but proving its terms is hard. When the customer is a consumer, what you say or write, and they rely on, can become part of the contract (CRA s.50). So the best protection is to write down exactly what you are promising, and what you are not.

What to include

• Your business name and address, your company number if you have one, and the client's name and the site address.
• Scope: a room-by-room or stage-by-stage description. Refer to drawings and a specification where you have them.
• Exclusions: what is not included (for example decorating, skips, client-supplied items, unforeseen ground conditions).
• Provisional sums for things you cannot price yet, clearly marked as such.
• Price and payment stages, each linked to a defined piece of finished work, and the payment terms. See getting paid.
• Dates and working hours, and what happens if the client causes delay.
• Responsibilities for planning, building control, party wall notices, and who pays the fees.
• Variations: how changes are requested, priced and approved.
• Cancellation information, if the contract is agreed away from your business premises. See cancellation rules.
• How disputes will be handled, and any guarantee you give.

Rules you cannot contract out of

With a consumer, you must do the work with reasonable care and skill, and you cannot exclude that liability (CRA s.49; s.57). An unfair term is not binding on the consumer (CRA s.62). Terms that are clear and balanced are more likely to be enforceable, and easier to rely on.

Variations (change orders)

Unrecorded changes are a frequent cause of payment arguments. A simple habit helps: no extra work starts until the change is written down and accepted. A short variation note can include:

• a reference number and date
• what is changing, and why
• the extra cost or saving
• any effect on the finish date
• the client's written acceptance (a signature, or a reply to an email or message)

Keep a running total of variations so the final account is no surprise to anyone.