Questions to Ask Your Builder Before You Hire Them

• “Can I see your public liability insurance certificate?” Minimum £2 million cover. Ask for the certificate, not just a verbal confirmation. Check the expiry date.
• “Do you have employers’ liability insurance?” Required by law if they have employees.
• “Are you a member of any trade body?” Federation of Master Builders (FMB), TrustMark, National Federation of Builders (NFB), or similar.
• “Are you registered with a competent person scheme for any trades?” If they will be doing electrical work (Part P), gas work (Gas Safe), or window installation (FENSA), they should be registered.

• “Have you done a project like mine before? Can I see photos?” You want a builder who has done similar work — same type of extension, same house style, similar scale.
• “Can I speak to two or three recent clients?” Good builders are happy to share references. Call them and ask about timelines, budget, and quality.
• “Can I visit a current or recently completed project?” Seeing their work in person tells you more than photos. Look at quality of finishes, tidiness, and attention to detail.

• “Is this a fixed-price quote or an estimate?” A quote is a fixed price for defined work. An estimate is a rough figure that can change. Always get a fixed-price quote.
• “What exactly is included in the price?” Go through the specification line by line. The most common disputes arise from assumptions about what is included.
• “What is NOT included?” Common exclusions: kitchen fitting, flooring, bathroom fittings, electrical upgrade, garden reinstatement, skip hire.
• “How do you handle variations and extras?” Changes during the build happen. Ask how they are priced and get the variation process in writing.

• “What is your payment schedule?” Expect stage payments tied to milestones (foundations complete, roof on, first fix, etc.). Never pay everything upfront. A typical structure: 10–15% deposit, then stage payments, with 5–10% retention.
• “Do you require a deposit? How much?” A deposit of 10–15% is normal to secure materials. More than 20% is a red flag.
• “How do I pay? And do you provide invoices?” Professional builders issue proper invoices. Be cautious of builders who only accept cash.

• “When can you start, and how long will it take?” Get specific dates, not “we’ll start in a few weeks.”
• “Will you be on site every day, or do you have other projects running?” Some builders run multiple jobs simultaneously, which can slow your project.
• “Who will be my main point of contact?” You need one person to talk to — the builder, a site manager, or a project manager.
• “Will you handle building regulations notifications and inspections?” Most builders handle this as part of their service.

• “Do you offer a guarantee on your work? How long?” Most reputable builders offer at least a 12-month defects liability period.
• “What happens if something goes wrong after you finish?” Understand the process. Is the guarantee insurance-backed (so it survives if the company closes)?

These are warning signs — not deal-breakers on their own, but patterns to be alert to:

• No written quote — only a verbal price or rough figures
• Large upfront payment — asking for 50% or more before starting
• No insurance certificates — “I’m covered” but cannot show proof
• Cannot provide references — or references that do not check out
• Pressuring you to decide quickly — “this price is only good today”
• No fixed address or landline — mobile-only with no business premises
• Significantly cheaper than other quotes — if one quote is 30%+ cheaper, find out why
• No written contract — any builder worth hiring will put the agreement in writing