Most homeowners go into a meeting with a potential builder and talk about the project. The builder talks about what they'd do, how they'd approach it, when they could start. And at the end, the homeowner has a general sense of whether they liked the person or not, but very little actual information about whether this contractor is right for this project.
What follows is a set of questions that produce specific, useful information. Good builders give good answers to these questions easily and without defensiveness. Builders who struggle with them are telling you something important.
Prepare the list before the meeting. Ask every candidate the same questions. Take notes. Compare answers afterwards. The process turns an impressionistic conversation into something much more evaluable.
About Experience and Qualifications
"Have you done similar projects recently? Can I see examples and speak to those clients?"
This is the most important question and you should take the reference-following seriously. A good answer gives you specific projects with contact details. A vague answer ("we do this type of work all the time") with no specifics or a reluctance to provide references is a red flag.
"Who will actually be on site doing the work? Will it be your own employees or subcontractors?"
Most contractors use a mix of direct labour and subcontractors. Neither is inherently problematic, but you want to understand who you're getting. If it's mostly subcontractors, ask how they vet and manage them. The quality of a subcontractor chain is a real variable in project outcomes.
"Are you registered with the Gas Safe Register / NICEIC / FENSA?"
Ask for the relevant registrations and verify them independently. See our guide on trade body memberships for which ones matter for which trades.
About This Project
"What do you see as the main risks or challenges in this project?"
This question separates builders who have thought carefully about your project from those who see it as a generic job. A good builder identifies site-specific challenges: the proximity to a neighbour's boundary, the likely ground conditions given the geology, the complexity of the structural junction with the existing house. A builder who says "no real issues, pretty straightforward" for a project that clearly has complications hasn't thought about it properly.
"What assumptions have you made in your quote?"
Every quote rests on assumptions. Ground conditions, access, programme duration, material specifications. You want to hear these stated explicitly. If a builder can't articulate their assumptions, variations during the build will be a constant and contested surprise.
"What's your current programme and when could you realistically start?"
Builders who are in demand have programmes. A realistic start date that's 8-16 weeks out is normal. An immediate start ("I can begin next week") from a contractor who claims to be well-established is worth probing. Why are they available immediately?
"How long do you expect this project to take?"
Note the answer. Ask what would cause it to take longer. Ask what mechanisms they use to keep to the programme. A builder who gives you a confident number without any caveats hasn't thought about it. A builder who gives you a realistic range with an honest discussion of what could affect it has.
About Communication and Management
"How do you communicate with clients during a build? How often, and by what means?"
There's no single right answer here, but the answer tells you a lot about the builder's approach. Regular written updates (weekly site reports or emails) are a positive sign. "We'll call if anything comes up" is less reassuring. You want to know that you'll be informed, not surprised.
"How do you handle variations and changes during the build?"
The answer should involve: written variation orders with a price before work proceeds, client sign-off before additional cost is incurred, and clear documentation. If the answer is "we sort it out as we go," that means undocumented cost additions that are very hard to challenge at invoice time.
"Who is my point of contact during the build? Will you be on site regularly?"
For a smaller firm, this may be the same person quoting. For a larger contractor, you may have a different site manager. Understand who you're dealing with day to day. If the person selling you the job won't be the person delivering it, factor that into your assessment.
Listen as much as you ask. How a builder talks about previous clients tells you how they'll talk about you once you're the client. Do they speak with respect? Do they take responsibility when things went wrong, or blame everyone else?
About Commercial Arrangements
"What are your payment terms?"
A legitimate payment schedule ties payments to progress milestones. A deposit of 10-25% at contract signing is reasonable for a significant project. Stage payments as work progresses are normal. Payment in full before completion, or large upfront payments that aren't tied to any progress, are not.
"Can you provide a certificate of public liability insurance?"
Ask this as a standard question, not as a challenge. A good builder produces it without hesitation. Check that it's current, that the cover level is adequate (minimum £2m), and that the named insured is the entity you're contracting with.
"What contract do you use?"
A builder who uses a standard JCT Homeowner Contract or similar is operating professionally. A builder who says "I just use my own terms" or "we don't bother with contracts" is not. You can propose using a standard form contract; a good builder will have no objection.
About References
"May I visit a project you're currently working on or have recently completed?"
A site visit reveals a lot: the quality of the work in progress, the tidiness and organisation of the site, and how the builder relates to the current client if they're present. Most reputable contractors are happy to arrange this. Those who aren't are protecting something.
When you call references, ask specifically:
- Did the project finish on or close to the quoted budget?
- Did it finish on or close to the agreed programme?
- How were variations handled?
- How did the builder communicate throughout?
- Were there any quality issues, and how were they resolved?
- Would you use them again?
That last question gets a straight answer from most people. If someone hesitates before saying yes, press them gently. The hesitation is the information.