Ask a builder about their legal identity and insurance, the exact scope and specification, who will be on site and when, how payments and variations work, who is handling statutory approvals, and what happens at completion. A builder who answers clearly and in writing is showing you how the whole job will run.
Why the questions matter more than the answers
Most homeowners judge a builder on manner and price. Both matter, but neither tells you how a job will actually run once it starts. The questions below are chosen because they force a builder to be specific — about who they are, what they will do, and what happens if something changes — rather than reassuring in general terms.
A good builder will not be offended by any of this. Answering clearly, in writing where asked, is itself useful information: it tells you how they run a job.
Identity and insurance
- 1. Are you a sole trader, a partnership, or a limited company, and what is the full legal name I'll be contracting with? A good answer is specific and matches what's on the quote — vague answers here are worth chasing further using the checks in our guide to checking a builder.
- 2. Can you give me your company number or, if a sole trader, confirm how long you've traded under this name? Verifiable answers can be checked against Companies House.
- 3. Do you hold public liability insurance, and can you send me the insurer's name and policy number so I can confirm cover directly with the insurer? A good builder provides this without hesitation.
- 4. If you employ staff, do you hold employers' liability insurance? This is a legal requirement for anyone with employees, per HSE guidance.
- 5. Are you registered for VAT, and will VAT be shown separately on quotes and invoices? Either answer can be legitimate; what matters is that it's stated plainly.
Scope and specification
- 6. Can I have a written specification setting out exactly what's included — materials, fittings, finishes — not just a total price? See our guide on what a builder's quote should include.
- 7. What is explicitly excluded from this price? A confident builder can list exclusions without prompting.
- 8. If I choose different materials or fittings partway through, how will the price change? Good answers describe a simple process, not a shrug.
- 9. Will you provide a fixed price, or is this an estimate that could move? The distinction matters — see quote vs estimate.
- 10. Are provisional sums included for anything (e.g. groundworks contingency), and how are they settled once the real cost is known?
Programme
- 11. What is the expected start date, and how firm is it? Good builders acknowledge that start dates can move and explain why.
- 12. How many working weeks do you expect the job to take? A specific number, with the caveats named, is better than an optimistic guess.
- 13. What could realistically delay the job, and how would you tell me if it happened?
- 14. Will you be working on other jobs at the same time as mine? An honest answer helps you judge how much attention your job will get.
- 15. What happens over holidays or bad weather — do those days extend the programme or are they already allowed for?
People on site
- 16. Who will actually be on site day to day — you personally, employed staff, or subcontractors? Good builders are candid about which trades are subcontracted.
- 17. Will the same people be present throughout, or will different trades come and go? Reasonable, provided you're told when handovers happen.
- 18. Who is my main point of contact if I have a question during the work?
- 19. Will there be a site manager or is it self-supervising? On smaller jobs, self-supervision by the builder themselves is normal.
- 20. Can I see the site or a recent completed job before work starts? A good builder is happy to arrange this, subject to a current client's agreement.
Payments and variations
- 21. What deposit, if any, is required, and what does it cover? See how much deposit should I pay a builder.
- 22. What is the stage payment schedule, and is each payment tied to a visible point in the work? Compare with our builder stage payment schedule guide.
- 23. How and when will extra or varied work be priced and agreed — verbally, or always in writing before it starts? A good answer insists on writing; see builder charging for extra work.
- 24. Is there a retention held back until snagging is complete, and how much?
- 25. What payment methods do you accept, and will I get an invoice or receipt for each payment?
Statutory approvals and completion
- 26. Does this work need Building Regulations approval, planning permission, or both, and who is responsible for arranging it? Confirm independently via the Planning Portal and your local Building Control.
- 27. Are you registered with a competent person scheme for any relevant trade (e.g. electrical, gas), and can I verify that directly with the scheme? See Gas Safe Register and NICEIC.
- 28. What guarantee or warranty applies to the finished work, and is it in writing?
- 29. What is the process for snagging — how are defects raised and how long do you have to fix them? See our building control completion checklist.
- 30. What certificates or documents will I receive at completion, and when?
Recording the answers
Ask these in one sitting where possible, and write the answers down against each builder you're comparing. A single vague or evasive answer isn't automatically disqualifying, but a pattern of vagueness across several questions is worth taking seriously — see our warning signs guide for what that pattern can look like.
Practical checklist
- Legal trading name and structure confirmed and matches the quote
- Public liability insurer and policy number obtained
- Employers' liability insurance confirmed if staff are employed
- VAT position stated clearly
- Full written specification requested, not just a total price
- Exclusions from the price listed explicitly
- Process for pricing variations agreed in advance
- Start date and expected duration given with caveats
- Main point of contact named
- Subcontracted trades disclosed
- Deposit amount and purpose explained
- Stage payment schedule tied to visible progress
- Retention arrangement discussed
- Statutory approvals responsibility clarified
- Competent person scheme membership offered for verification
- Guarantee or warranty terms requested in writing
- Snagging process explained
- Completion documents and certificates listed
Good and bad examples
What good looks like
"I'm a limited company, here's my company number, and here's my insurer's contact if you'd like to confirm cover. The specification lists fittings by make and model, groundworks contingency is a provisional sum settled against invoice, and any extra work is priced and agreed in writing before we start it."
What to push back on
"Don't worry about all that, I've been doing this thirty years, you can trust me" — offered instead of any of the specific answers above.
Worked example
Illustrative example of scoring three builders' answers to the same questions
| Question theme | Builder A | Builder B | Builder C |
|---|---|---|---|
| Insurer details provided | Yes, checked directly | Only a logo shown | Yes, checked directly |
| Written specification | Full, itemised | One-line total only | Fairly detailed |
| Variations process | Written agreement each time | "We'll sort it as we go" | Written agreement each time |
| Overall impression | Clear and specific | Vague on several points | Clear and specific |
Commonly missed items
- Not asking who is legally responsible if a subcontractor's work fails
- Not asking how price changes are agreed before assuming a fixed price covers everything
- Forgetting to ask about weather and holiday allowances in the programme
- Not confirming who arranges Building Regulations sign-off
- Failing to ask what happens if the builder is unwell or unavailable mid-project
Warning signs
- Reluctance to give an insurer's name or policy number
- Refusal to put a specification or exclusions in writing
- Insistence that variations can be agreed verbally only
- Evasiveness about who will actually be doing the work
- No clear answer on statutory approvals
Questions to ask
- Can you provide your insurer's name and policy number for me to verify?
- What exactly is excluded from this price?
- Who will be on site day to day?
- How are variations priced and agreed?
- What documents will I receive at completion?
When to seek professional advice
- If a builder refuses to answer several of these questions in writing
- If insurance cannot be verified directly with the named insurer
- If the specification cannot be pinned down before you're asked to sign
- If you're unsure whether the job needs planning permission or Building Regulations approval — check with the Planning Portal or your local Building Control
Official sources
Frequently asked questions
- Should I ask all 30 questions of every builder I get a quote from?
- Ideally yes, at least in condensed form, so you're comparing like for like. It also makes it obvious when one builder is noticeably vaguer than the others.
- Is it rude to ask for insurance details?
- No. Established builders are used to this and can usually provide it in a couple of minutes. See our guide on how to check a builder for how to verify it independently.
- What if a builder gives good verbal answers but won't put anything in writing?
- Treat that as a warning sign in itself. Verbal reassurance is not evidence, and a written record protects both sides if there's a disagreement later.
- Do I need to ask these questions if I'm using a builder a friend recommended?
- Yes. A personal recommendation is useful but doesn't replace checking insurance, specification and payment terms for your specific job.
- What should I do with the answers once I've collected them?
- Keep them alongside the written quote. If the builder is engaged, ask for the specification and payment terms to be reflected in the written contract.
Builder Proof UK publishes general educational information for homeowners. It is not legal, structural, surveying, planning, electrical, gas, insurance or financial advice, and it does not replace advice from a suitably qualified professional for your specific project.