Most homeowners starting a renovation have a vague awareness that they should probably have a contract. Fewer know that there's already a well-established, legally robust framework designed specifically for their situation. The JCT (Joint Contracts Tribunal) produces a suite of contracts used across the UK construction industry, and two of them are particularly relevant if you're employing a builder directly for domestic work: the Minor Works Building Contract and the Homeowner Contract series.
Understanding which to use, and how to use it properly, is one of the most valuable things you can do before a single brick is moved.
Which JCT Contract Do You Need?
JCT publishes two options that most homeowners will encounter:
The JCT Homeowner Contract (HO) is designed for smaller domestic jobs where you're employing a contractor without the involvement of an architect or consultant. It comes in two versions: one for work with a consultant and one without. The language is deliberately straightforward, and JCT has made an effort to make it accessible to non-professionals. It covers projects typically up to around £150,000 or so, though there's no absolute cap.
The JCT Minor Works Building Contract (MW) is a step up in complexity and is better suited to projects where a consultant (architect, structural engineer or project manager) is administering the contract on your behalf. If your build involves a professional team, this is more likely to be appropriate.
For the majority of homeowners doing a kitchen extension, loft conversion or significant renovation without a full professional team, the Homeowner Contract is the right starting point.
What the Contract Actually Covers
A JCT contract is not simply a payment schedule. It's a comprehensive document that sets out the obligations of both parties from start to finish. The key provisions include:
The works description and drawings. The contract references your specification documents explicitly. This is critical. The contract is only as good as what it incorporates. If your brief is vague, the contract provides no protection against a builder who interprets it however suits them.
The contract sum. The agreed price for the work described. Any change to the scope of work must be treated as a variation and priced separately before it's carried out. We'll come back to that.
The commencement and completion dates. Not just when work starts, but when it's due to finish. The contract allows you to claim compensation for delays caused by the contractor, within defined limits.
Payment provisions. Stage payments, payment notices and payment periods. The contract sets out how and when the contractor is entitled to be paid, and what happens if payment is withheld.
Insurance requirements. The contract specifies what insurance the contractor must hold. This is often overlooked by homeowners who simply take a contractor's word for it.
Defects liability period. Typically six or twelve months after practical completion, during which the contractor is obliged to return and fix any defects that emerge. This is separate from your legal rights under consumer law, but provides a contractual mechanism to enforce repairs.
Termination provisions. The circumstances under which either party can end the contract. These are tightly defined and not something to invoke lightly, but it's vital you know they exist.
Variation Orders: The Most Important Section
In practice, the variation order provisions are what protect you most during the build itself. A variation is any change to the originally agreed scope of work: adding a rooflight you didn't originally include, switching from tiled flooring to engineered oak, or knocking through a wall that wasn't in the original plan.
Under the JCT framework, no variation can be instructed without a written order, and the contractor has no obligation to carry out the work until the value is agreed. This is where many informal arrangements fall apart: the contractor does extra work, presents a bill at the end, and the homeowner has no record of having agreed to it or the price.
Practical tip: Even if you're using a JCT contract, agree a simple variation order form with your contractor at the start. One page: description of the change, agreed cost, agreed impact on programme, signatures from both parties. Keep every signed copy.
Filling in the Contract Properly
A blank JCT form does nothing. It's only effective once the Schedule (the section at the back where you fill in the project-specific details) is completed correctly. Common mistakes include:
- Leaving the specification documents unspecified: "as per builder's quote" is not a specification. List every drawing, schedule and document by name and date.
- Using an unrealistic completion date without allowing for weather, supply delays or unforeseen structural issues. Build in float if you can.
- Forgetting to complete the insurance section. Check what your builder actually holds, verify it and record it in the contract.
- Agreeing a contract sum without agreeing a payment schedule. Stage payments should be defined before work starts, not negotiated as the build progresses.
What a JCT Contract Does Not Do
A contract doesn't prevent disputes. It provides a framework for resolving them. If a contractor simply disappears or ignores their obligations, having a JCT contract gives you a far stronger position in adjudication, mediation or court proceedings. But you still have to pursue it.
A contract also can't compensate for a poor specification. If your brief was vague and the builder has produced something that matches what was written down, even if it doesn't match what you envisioned, the contract may not help you. The protection comes from a thorough brief, not just from the document.
Where to Get One
JCT contracts are available directly from JCTltd.co.uk. The Homeowner Contract costs around £30 to download. It's one of the best-value purchases you'll make on your entire project.
Some solicitors who specialise in construction will review and annotate a JCT contract for you. For projects over £50,000, an hour of that advice is money well spent. For smaller projects, downloading the contract, reading it carefully and completing the Schedule accurately will give you substantially more protection than no contract at all.
Do not: Let a contractor talk you out of using a proper contract on the basis that "we work on trust." A legitimate contractor has nothing to fear from a fair, standard contract. Resistance is a warning sign.
What Happens When There's a Dispute
JCT contracts include an adjudication provision. Adjudication is a fast-track dispute resolution process: a qualified adjudicator reads both sides' submissions and makes a binding decision, usually within 28 days. It's not cheap (adjudicators' fees typically run to several thousand pounds), but it's substantially faster and cheaper than litigation. The Homeowner Contract also allows for mediation as a first step, which costs considerably less.
If you reach the point of a dispute, having a properly executed JCT contract will determine whether you have a case worth pursuing. Without one, you're relying on witnesses, WhatsApp messages and general consumer law. With one, you have a document that sets out exactly what was agreed and what was breached.
It's not a perfect system. Nothing in construction is. But it's the best available tool for a homeowner managing a domestic build, and ignoring it is an unnecessary risk.