How to Write a Contract for a Building Job
Most tradespeople never use a written contract. They agree a price, shake hands, and get on with the job. And most of the time that works fine – until it doesn’t. When a customer disputes the price, refuses to pay, or claims the work wasn’t what they agreed to, the absence of a written contract leaves you with very little protection. A simple written contract doesn’t need to be complicated or written by a solicitor. It just needs to clearly set out what was agreed, what it costs, and what happens if things go wrong.
Why Tradespeople Need Written Contracts
Clear expectations
Both you and the customer have agreed in writing exactly what work is being done, what’s included, what’s excluded, and what it costs. No room for “I thought that was included” conversations later.
Protection if they don’t pay
If a customer refuses to pay and you take action through Small Claims Court or a debt recovery service, a signed contract is your strongest evidence. Without it, it’s your word against theirs.
Protection from scope creep
Customers sometimes try to add extra work without acknowledging it should cost more. A contract that clearly defines the scope makes it simple to say “that’s outside what we agreed.”
Looks professional
Presenting a clear, professional contract builds customer confidence. Customers who might have hesitated about a large project feel more comfortable when they can see exactly what they’re signing up for.
What to Include in a Contract for a Building Job
You don’t need legal jargon or a ten-page document. A clear, straightforward contract covering these sections is sufficient for most trade jobs.
1. Your business details
Full name or business name, address, phone number, email, and any relevant registration numbers – Gas Safe, NICEIC, Companies House if you’re a limited company.
2. Customer details and job address
The customer’s full name and address, including the address where the work is being carried out if different.
3. A detailed description of the work
This is the most important section – and the one most commonly done badly. Don’t write “bathroom refurbishment.”
Good example
“Remove existing bath, toilet, and basin. Supply and fit new shower enclosure, back-to-wall toilet unit, and pedestal basin. Tile walls to full height with customer-supplied tiles. Tile floor with customer-supplied tiles. Connect all pipework and test. Make good any areas disturbed in the course of the works.”
4. Exclusions – what’s NOT included
Just as important as what you will do. Clearly listing exclusions prevents customers from claiming work was included when it wasn’t. Common exclusions: making good plasterwork beyond the immediate work area; decorating after completion; removing customer-supplied materials; any additional work arising from unforeseen conditions discovered during the job.
5. Materials
Who is supplying materials – you or the customer? If you’re supplying, note whether the price is fixed or subject to change. If the customer is supplying, make clear that delays from late delivery are outside your control and may affect the programme.
6. Price and payment terms
State the total price clearly – VAT inclusive or exclusive. Include: deposit amount and when it’s due; any stage payments for larger jobs; final payment timing; payment method; and the due date for payment (e.g. “within 7 days of invoice.”)
7. Start date and completion estimate
Expected start date and estimated completion date – making clear that completion is an estimate subject to factors outside your control (weather, material availability, unforeseen site conditions).
8. Variations clause
Any changes to the agreed scope must be agreed in writing before work proceeds, and may affect the price and programme. This is your protection against customers asking for extras and then refusing to pay for them.
9. Cancellation terms
What happens if the customer cancels after you’ve started, or after you’ve ordered materials? Include notice period required, what costs are recoverable if they cancel, and your right to retain the deposit if they cancel without reasonable notice.
10. Disputes and complaints
A simple process for raising and resolving complaints – issues should be raised in writing within a set number of days of completion and you will respond within a set timeframe. Some trade associations offer mediation services for members.
Simple Contract Template
Contract for Building Works
Contractor:[Your name / business name / address / contact details]
Customer:[Customer name / address]
Date:[Date]
1. Description of Works[Detailed description of exactly what work will be carried out]
2. ExclusionsThe following are specifically excluded from this contract: [List exclusions]
3. Materials[Who supplies materials, and any relevant conditions]
4. Contract PriceThe total price for the works described above is £[amount] [plus VAT at 20% = £[VAT amount] / inclusive of VAT].
5. Payment TermsDeposit of £[amount] due on signing · Balance of £[amount] due within [X] days of completion · Payment by [bank transfer / card / cash]
6. ProgrammeExpected start date: [date] · Estimated completion: [date] – subject to unforeseen site conditions and material availability
7. VariationsAny changes to the agreed scope of work must be agreed in writing before proceeding. Variations may affect the contract price and programme.
8. Cancellation[Your cancellation terms]
9. Disputes[Your complaints and dispute resolution process]
Signed by Contractor:_________________________ Date: _________
Signed by Customer:_________________________ Date: _________
How to Present a Contract Without Making Customers Uncomfortable
Done right, presenting a contract builds confidence – not suspicion. Keep the language plain English. Walk the customer through what’s in it before asking for a signature – five minutes explaining what work is included, what’s excluded, and how payment works demonstrates professionalism and gives them the chance to ask questions before you start. Send your contract alongside your quote so they can review both together. Digital signing tools like DocuSign or Adobe Sign let customers sign from their phone and return the contract immediately. Tradify lets you attach documents to quotes and send them professionally in one go.
Try Tradify Free for 14 Days →What If a Customer Refuses to Sign?
For small jobs – a few hundred pounds – a detailed quote accepted in writing (even by email or text) provides some protection and it’s not worth making a contract a sticking point. For larger jobs – anything over £1,000 – a signed contract is worth insisting on. A customer who refuses to sign a reasonable contract before a large job is a red flag worth taking seriously before you commit.
Frequently Asked Questions
Not necessarily for every job – for small jobs of a few hundred pounds, a detailed written quote accepted by email or text provides adequate protection. But for any job over £1,000, a signed written contract is strongly recommended. The larger the job, the higher the risk of a dispute about scope, price, or payment – and a signed contract is your strongest protection in any of these situations. Make it a standard part of your process for any significant job and customers will come to expect it as a sign of professionalism rather than distrust.
Ten key sections: (1) your business details and any trade registrations; (2) customer details and job address; (3) a detailed description of the work to be carried out; (4) a clear list of exclusions – what is NOT included; (5) who is supplying materials; (6) the total price and payment terms (deposit, stage payments, final payment, due date); (7) expected start and estimated completion dates; (8) a variations clause covering how changes to scope are agreed and priced; (9) cancellation terms; (10) a complaints and dispute resolution process. Both parties should sign and keep a copy.
For most standard building jobs, you can write your own contract using clear, plain English – you don’t need a solicitor. The template structure in this guide covers all the key elements. What matters is that it clearly sets out what was agreed so both parties know exactly where they stand. For unusually high-value or complex projects, or if you’re ever unsure about specific terms, your trade association may be able to review a standard contract template – many provide their own contract templates to members as part of membership.
A variations clause specifies how changes to the agreed scope of work are handled. A typical clause states: “Any changes to the agreed scope of work must be agreed in writing between both parties before work proceeds. Variations may affect the contract price and programme.” This is your protection against customers requesting extra work during a job and then refusing to pay for it, or claiming it was included in the original price. Without a variations clause, any additions to the scope can become a source of dispute. With one in place, all changes are agreed and priced before you proceed.
Yes – electronic signatures are legally valid in the UK under the Electronic Communications Act 2000. Digital signing tools like DocuSign and Adobe Sign let customers sign contracts from their phone and return them immediately – significantly faster and more convenient than paper. You receive a timestamped, signed copy automatically. Sending contracts digitally alongside your quote (using a tool like Tradify) means customers can review and sign everything at the same time, and you have a clear digital record of when they agreed to the terms.
This guide provides general information and is not legal advice. For high-value jobs or specific legal questions, speak to a solicitor or your trade association. Some links on this page are affiliate links; if you sign up through them we may earn a commission at no extra cost to you.