How to check a builder before hiring them
Before appointing a builder, check both the business and the proposal for your particular job. A recommendation or impressive portfolio is a useful starting point, but it does not establish who will do the work, what is included or whether the proposed programme is credible.
Confirm who you are contracting with
Ask for the legal business name, trading name, correspondence address and the person responsible for the job. If it is a limited company, check the company number and filing information on Companies House. The register confirms identity and filings; it is not a guarantee of workmanship or financial health. A sole trader will not have a company number.
Make sure the name on the quote, proposed contract, invoice and payment details is consistent. If it changes, ask why before paying.
Test relevant experience, not just photographs
Ask for recent projects similar in scope and complexity to yours. A builder experienced in simple extensions may still need a credible plan for an occupied loft conversion with structural alterations, multiple trades and weather protection. Ask what the builder personally managed, which subcontractors were used and what problems arose.
Speak to more than one previous client where possible. Ask about communication, changes, defects, payment requests and whether the final cost and finish date matched the original proposal. A completed-project visit is more useful when the owner can explain how the work actually went.
Check the proposed team and capacity
Who will supervise day to day? Which trades will be employed or subcontracted? How many jobs will the builder run at once? Ask for a programme showing the main stages, lead times and dependencies. A short finish date is credible only if the resources and sequence support it.
Ask how the site will be protected, how access and waste will be managed, and what happens if a key trade is unavailable. These questions reveal whether the quote was built around your house or a generic price.
Review insurance and credentials in context
Ask for current insurance evidence appropriate to the work and check the insured name, activity, period and limits. Where a scheme membership, trade qualification or guarantee is claimed, verify it through the issuer and understand what it covers. A badge alone is no substitute for clear scope and reliable references.
Specialist design, electrical work, gas work or other regulated tasks need the right competent person and documentation. Establish who arranges those people and who supplies the evidence at handover.
Put the appointment on paper
Compare the quote with the drawings and specification. Identify exclusions, allowances, client purchases, contract, payment stages, variation process and defect arrangements. Our quote checklist tests completeness; the comparison guide helps when several builders have priced different scopes.
Do not pay a booking or mobilisation amount until you understand what it secures, when it can be used and what happens if the start date or scope changes. A builder can reasonably need funded procurement and mobilisation, but the arrangement should be explicit and documented.
Need an independent comparison?
Build Advocate’s Complete Builder Selection compares up to three builders, examines missing scope and due diligence, and reviews proposed contract, payment and programme information. We have no financial stake in which builder you appoint.
