If you are planning an extension, renovation or structural repair, the best questions to ask a builder are the ones that reveal how they work, what is included in the price, and how they handle problems if they arise. The short answer: ask about experience, insurance, references, written quotations, payment terms, who will manage the job, and what happens if the scope changes.
That matters because hiring a builder is not just about finding someone available. It is about choosing a professional who can deliver the work safely, legally and to the standard you expect. In the UK, some projects may also involve building regulations, planning permission or specialist trades, so you want clarity before any money changes hands.
This guide gives you 10 practical questions to ask before hiring a builder, plus what good answers should look like. If you are still at the search stage, you can also find local tradespeople or browse the builders directory to compare options.
1. Have you done similar projects before?
Not every builder specialises in every type of work. A contractor who is excellent at small refurbishments may not be the right fit for an extension, loft conversion or structural alteration.
Ask them to describe projects similar to yours in size, type and complexity. If your job involves older properties, ask whether they have experience working with traditional materials, damp issues or restricted access.
- What similar jobs have you completed in the last 12 months?
- What part of the work did you handle directly?
- Were there any difficult issues, and how were they resolved?
Look for specific, relevant examples rather than vague reassurance.
2. Are you insured, and what does the cover include?
Insurance is one of the most important checks before work begins. A responsible builder should be able to explain what cover they hold and provide evidence if asked. At a minimum, ask about public liability insurance and any other cover relevant to the project.
Do not assume that every problem is automatically covered. Insurance can differ in scope, exclusions and limits. If a builder uses subcontractors, ask whether they are insured too.
This is a sensible place to slow down and verify details rather than taking a verbal promise at face value. For general consumer guidance on choosing traders, see how to check if a tradesperson is legitimate in the UK.
3. What exactly is included in the quotation?
A good quotation should clearly show the scope of work, materials, labour, VAT position if applicable, and any assumptions made. The more detailed the quote, the easier it is to compare builders fairly.
Ask whether the quote includes:
- Site preparation and waste removal
- Materials and product brands or grades
- Labour, supervision and subcontractors
- Scaffolding, skips or access equipment
- Decorating, making good and final clean-up
If anything is unclear, ask for it to be put in writing. A lower quote can look attractive, but if it excludes essential items, it may not be the best value.
4. Who will actually manage the job on site?
You may speak to one person during the quoting stage but work with someone else once the project starts. Find out who will be your day-to-day contact, who supervises the work, and who makes decisions if issues arise.
Ask whether the builder uses subcontractors for parts of the job such as electrics, plastering, plumbing or roofing. That is normal on many projects, but you should know who is responsible for coordination and quality control.
Clear site management helps reduce delays, misunderstandings and duplicated work.
5. What is your payment schedule?
Payment terms should be sensible, staged and documented. Be cautious if someone wants a large upfront payment without a clear reason. For larger projects, a structured payment schedule linked to milestones is usually easier to manage than a vague arrangement.
Before agreeing, ask:
- How much deposit is required?
- When are stage payments due?
- What happens if there is a delay or a dispute?
- Do you provide receipts and written confirmations?
Never pay in full before the work has begun unless you fully understand the risks and the written terms.
6. Can you provide recent references or examples of completed work?
References are useful, but only if they are recent and relevant. Ask for examples of completed projects that are similar to yours, ideally with photos and client contact details where appropriate.
When speaking to previous customers, ask practical questions such as:
- Was the job finished on time?
- Was the builder easy to contact?
- Were variations explained clearly?
- Would you hire them again?
Be cautious if a builder only offers old references or cannot show recent work. A strong portfolio should be easy to discuss.
7. How do you handle changes, extra work or unexpected problems?
On renovation and building projects, surprises are common. Hidden defects, damp, poor previous repairs or structural issues can all change the scope of work. That is why you need a clear process for variations.
Ask how extra work is priced, who approves it, and whether any changes will be confirmed in writing before proceeding. This protects both sides and reduces the chance of disagreement later.
If the builder cannot explain how they manage changes, that is a warning sign.
8. What is the expected timescale, and what could delay it?
Timeframes should be realistic, not optimistic guesses. Ask when the job can start, how long each stage should take, and what might cause delays. Weather, material shortages, access issues and design changes can all affect a build.
A useful builder should be able to explain their schedule, including any dependencies on other trades or approvals. If your project needs building control involvement, design sign-off or specialist subcontractors, that should be built into the timeline from the start.
9. Will you put everything in a written contract?
Yes — ideally. A written agreement helps prevent disputes by setting out the scope, cost, schedule, payment terms, and responsibilities of both parties. It also gives you something to refer back to if expectations change.
Before work starts, make sure you understand:
- What is included and excluded
- Start and completion dates
- How variations are handled
- Payment milestones
- How complaints or defects will be addressed
For consumer rights and what to do if something goes wrong with a trader, Citizens Advice has helpful guidance on contracts and disputes. In Scotland, building work can also involve different procedures from England for some planning and building control matters, so check the rules that apply to your location.
10. Are there any legal or regulatory issues I should know about?
Some building projects need planning permission, building warrant approval in Scotland, or building regulations approval in England and Wales. The builder may help, but it remains your responsibility as the homeowner to understand what approvals are needed before work starts.
For example, structural changes, extensions and some alterations can trigger formal requirements. If your project includes gas work, that should be handled by a Gas Safe registered engineer where required. Electrical work should also be carried out by someone suitably competent, and certification may be needed depending on the job.
Useful official sources include GOV.UK for England and Wales guidance, mygov.scot for Scottish guidance, and the Health and Safety Executive for safety information. For gas safety, check the Gas Safe Register; for electrical safety guidance, see Electrical Safety First.
A simple builder comparison checklist
When you have more than one quote, compare the builders using the same criteria:
- Similar experience with jobs like yours
- Clear written quotation
- Appropriate insurance
- Recent references or examples
- Realistic timeline
- Clear payment terms
- Named person managing the work
- Written contract and variation process
If one quote is much lower than the rest, ask why. It may reflect a different specification, missing items, or an approach that is too optimistic.
FAQs
How many builders should I get quotes from?
For most projects, comparing at least three quotes gives you a better sense of price, scope and professionalism. Make sure each builder is pricing the same work.
Should I choose the cheapest quote?
Not automatically. A cheaper quote can be good value, but only if it includes the same scope, materials and level of service as the others. Compare the detail, not just the total.
What warning signs should I watch for?
Be cautious if a builder pressures you to decide immediately, avoids written quotes, asks for large cash payments, or cannot explain their insurance, timetable or subcontractors clearly.
Do I need a contract for small jobs?
Even for smaller jobs, a written summary of the work, price and payment terms is sensible. It need not be complex, but it should be clear.
Final thoughts
The best questions to ask a builder are the ones that turn a sales conversation into a practical decision. If the answers are clear, specific and written down, you are in a much stronger position to choose confidently and avoid misunderstandings later.
For a straightforward next step, use Trusted Trader Hub to find local tradespeople or view the builders directory as you compare your options. If you are a builder yourself, you can also promote your trade business or join Trusted Trader Hub.
