10 Questions to Ask Before Hiring a Construction Company

When a homeowner tells me they hired their last builder based on "a good feeling" and a low quote, I already know how the story ends. Choosing the right builder comes down to asking the right questions—and knowing what the answers should sound like. Here are the ten questions I'd ask if I were in your shoes.

1. "How long have you been trading, and can I check your company details?"

Why it matters: Longevity isn't everything, but it's something. A builder who's been trading for 10+ years has survived recessions, difficult clients, and material shortages. They've figured out how to run a sustainable business.

Good answer: "We've been trading since 2014. Here's our Companies House number—you can look us up." They should be open about their history.

Bad answer: "Oh, I've been doing this for years." Vague, no specifics, reluctant to provide company details.

2. "Can I see your public liability and employer's liability insurance certificates?"

Why it matters: Without valid insurance, you're taking on enormous personal risk. If a worker is injured on your property or your neighbour's wall collapses, you could be liable.

Good answer: "Of course—I'll email them over today. Public liability is £5 million, employer's is £10 million." They should have these ready.

Bad answer: "I'm fully insured, don't worry about it" but can't produce documentation. Or the dates on the certificate have expired.

💡 Builder's Truth: I keep PDF copies of all our insurance and certifications on my phone. Any professional builder should be able to share these within minutes, not days.

3. "What similar projects have you completed, and can I visit one?"

Why it matters: A builder might be excellent at bathroom refurbishments but have never done a loft conversion. You want someone with specific experience in your type of project.

Good answer: "We did three loft conversions in Lewisham last year—here are the addresses. Mrs. Okonkwo at number 42 said she'd be happy to show you around."

Bad answer: "We've done loads of lofts" but can't provide any specific addresses or contacts.

4. "Who will actually be on site day-to-day?"

Why it matters: The person quoting the job often isn't the person doing the work. You need to know who'll be in your home every day, and who to contact if there's a problem.

Good answer: "I'll be your main point of contact and on site at least twice a week. Dave is our site supervisor—he'll be there daily, and here's his mobile number."

Bad answer: "One of my guys will sort it." No names, no direct contact details, vague about supervision.

5. "What's your realistic timeline, and what could delay it?"

Why it matters: Honest builders know that delays happen. Weather, material shortages, building control inspections—these are realities. What you want is transparency.

Good answer: "Based on similar projects, I'd estimate 10-12 weeks. The main risks are building control availability—currently running 2-3 weeks behind in Southwark—and if we find any structural surprises once we open up."

Bad answer: "Six weeks, definitely." Unrealistic timelines suggest either inexperience or telling you what you want to hear.

6. "How do you handle variations and extra costs?"

Why it matters: This is where projects go sideways. Every renovation uncovers surprises—rotten joists, old wiring, asbestos. How these are priced and communicated makes the difference between a good experience and a nightmare.

Good answer: "Anything outside the agreed scope gets a written variation order before we proceed. I'll explain what we've found, give you a price, and you decide. Nothing extra gets charged without your approval."

Bad answer: "We'll sort it out as we go" or "extras are charged at day rate." This is how a £50,000 project becomes £75,000.

💡 Builder's Truth: I always include a contingency allowance in my discussions—typically 10-15% for refurbishments, 5-10% for new builds. If a builder doesn't mention contingency, they're either naïve or planning to hit you with extras later.

7. "What does your payment schedule look like?"

Why it matters: Payment structures protect both parties. You shouldn't pay too far ahead of completed work, but the builder also needs cash flow to pay for materials and labour.

Good answer: "We work on staged payments linked to milestones: 15% deposit, then payments at structural completion, first fix, second fix, and final completion with retention for snagging."

Bad answer: "50% upfront" or payments based on time rather than completed work.

8. "Will you be handling building regulations and what certifications will I receive?"

Why it matters: Without proper sign-offs, you'll have problems selling your home. Electrical work needs Part P certification. Gas work needs Gas Safe certificates. The loft conversion needs building regulations completion.

Good answer: "We handle the building control application and all inspections. At the end, you'll receive the building control completion certificate, Part P electrical certificate, and Gas Safe certificate for the boiler. All originals, with copies kept on file."

Bad answer: "You don't need to worry about that" or "We'll sort the paperwork later." Paperwork forgotten during the build is often paperwork never completed.

9. "What happens if something goes wrong after you've finished?"

Why it matters: Even the best work can develop issues—a door that drops, a crack that appears as the building settles, a leak that wasn't apparent. You need to know your builder will come back.

Good answer: "We have a 12-month defects liability period. Any issues that arise from our workmanship, call us and we'll fix them. Beyond that, I'm still a phone call away—we've got clients from ten years ago who still get in touch."

Bad answer: "Give us a call" (non-committal) or no mention of any guarantee period.

10. "Can you provide a written, itemised quotation?"

Why it matters: A single-line quote of "Loft conversion: £65,000" tells you nothing. You can't compare it fairly to other quotes, you don't know what's included, and there's no basis for discussing variations.

Good answer: A detailed breakdown: demolition and strip-out, structural works, roofing, windows, insulation, electrics, plumbing, plastering, carpentry, decoration, each with a figure. Plus clear statements of what's excluded.

Bad answer: A vague one-page letter with a single total, or verbal quotes only.

💡 Builder's Truth: Writing a detailed quote takes time—often a full day for a complex project. If a builder sends a comprehensive breakdown, that's a sign they've properly thought through your job. If they send a single number the same afternoon, they haven't.

Quick Reference Checklist

Before you sign anything, make sure you can tick all of these:

✓ Verified company details on Companies House
✓ Seen valid insurance certificates
✓ Visited or spoken to a previous client
✓ Know who will be on site daily
✓ Have a realistic timeline with caveats
✓ Understand how variations are handled
✓ Payment schedule is milestone-based, not front-loaded
✓ Building regs and certificates are included
✓ Defects period is specified in writing
✓ Quote is itemised and detailed

Taking an extra few hours to vet your builder properly can save you months of stress and thousands of pounds. The right builder will welcome your questions—they're a sign of a client who takes their project seriously.

Got Questions?

If you're working through this list and want to sense-check something, or if you've got a project in mind and want some initial guidance, I'm happy to chat. No hard sell—just straight answers.

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