How to choose a builder in the UK

No licence exists, so build your own checks

There is no register you must appear on to trade as a builder. Schemes such as TrustMark, and membership bodies including the Federation of Master Builders, provide vetting and a complaints route, but they are voluntary. Their value is real; their absence is not proof of anything.

Practical verification is more useful than logos: a registered company you can look up on Companies House, a VAT number if they should have one, a verifiable address, and recent work you can actually go and look at.

Building control and planning are separate things

Planning permission concerns whether you may build what you propose. Building control concerns whether the construction meets the Building Regulations. Many projects need building control approval without needing planning permission.

Agree explicitly, in writing, who applies for what, who pays the fees, and who is present for inspections. Unapproved structural work is expensive to regularise and routinely surfaces when you come to sell.

What the contract should cover

For anything beyond a small job, a written contract protects both sides. Standard forms exist for domestic building work and are a reasonable starting point if neither party wants to draft one.

• A detailed scope of works, with drawings or a specification attached.
• The total price, and how variations will be priced and agreed.
• A payment schedule tied to completed stages, not calendar dates.
• Start and completion dates, and what happens if they slip.
• Who supplies materials, and to what specification.
• Working hours, site access, skip placement and waste removal.
• A retention held back until snagging is complete.
• Insurance held by both parties.

Payments: the single biggest risk

Paying substantially in advance is the most common way homeowners lose money on building work. A deposit toward materials is normal; paying a large share of the total before work begins is not.

Tie payments to visible, completed stages: foundations, damp course, roof watertight, first fix, plaster, second fix, and inspect before releasing each. Hold a retention of a small percentage for a period after completion to cover snagging. Where possible, use a payment method with some recourse rather than a bank transfer.

Warranties and guarantees

A guarantee is only as good as the entity standing behind it. A builder’s own guarantee ends if the business does. Insurance-backed guarantees, offered through some trade schemes, survive the builder ceasing to trade.

New homes and major conversions are often covered by a structural warranty from a provider such as NHBC. For extensions and renovations, ask specifically what is warranted, by whom, and for how long.

Warning signs

• Pressure to decide immediately, or a discount that expires today.
• A quote given verbally, or a refusal to itemise.
• A demand for a large cash payment up front.
• No fixed address, or only a mobile number.
• Cold-calling at the door, particularly about roofs or driveways.
• Reluctance to involve building control on work that plainly requires it.