How to Find a Builder Who Won’t Let You Down

You can have the most beautiful architectural drawings in the world, but if you choose the wrong builder, your dream extension can quickly turn into a nightmare.

We have all heard the horror stories: projects running months over schedule, budgets spiralling out of control, or builders simply vanishing halfway through the job.

But it does not have to be that way. There are thousands of fantastic, skilled tradespeople out there—you just need to know how to filter them out from the cowboys.

Here is our step-by-step guide to finding a builder you can trust.

1. Start with “Real World” Reviews

Online reviews are useful, but they can be faked. The best recommendation comes from someone you know.

• Ask the neighbours: If you see a signboard on a street near you, knock on the door. Ask the homeowner: Did they turn up on time? Were they tidy? Did the price change?
• Look for the badge: Membership in a trade body like the Federation of Master Builders (FMB) is a good sign. It means they have been vetted, inspected, and have to stick to a code of conduct.

2. Do not Trust the Photos—Trust the Site

Any builder can post a glossy photo of a finished kitchen on Instagram. But that photo does not tell you if the roof leaks or if the site was a dangerous mess for three months.

The Test: Ask to visit a current site.

• Is it organised and relatively tidy?
• Are the materials stored properly?
• Are the workers professional? If a builder refuses to let you see their work in person, treat that as a red flag.

3. The Quote: Avoid the “Estimate” Trap

You ask three builders for a price. Two come in at £60k, and one comes in at £40k. You go with the cheaper one, right?

Wrong. The low quote is often low because it is missing things. It might be an “estimate” rather than a fixed quote, or it excludes essentials like skip hire, painting, or VAT.

Make sure every quote includes:

• A breakdown of labour vs. materials.
• Exactly what is included (e.g. “supply and fit 4 spotlights”) and what is excluded (e.g. “final flooring”).
• A waste management plan (skips and disposal).

4. The Paperwork: Contracts and Insurance

Never, ever work on a handshake. It might feel friendly, but if things go wrong, a handshake offers you zero protection.

• The Contract: Use a standard written contract (like a JCT Homeowner contract or the FMB’s plain English version). This sets out the start date, the finish date, and exactly when you need to pay.
• The Insurance: Ask to see their Public Liability Insurance certificate. If they accidentally put a spade through your main water pipe or damage your neighbour’s car, you need to know they are covered.

5. Payment Terms: Keep Control

A reputable builder will never ask for the entire amount upfront. Instead, agree on a payment schedule tied to milestones. For example:

• Ten percent Deposit to book the slot.
• Payment 2: When foundations are poured.
• Payment 3: When the roof is on (watertight).
• Final Payment: Only when the job is finished and you are happy with the “snagging” list.

6. The “Vibe Check”

This sounds unscientific, but it matters. You are going to have these people in your house at 8:00 AM every day for several months.

• Do they communicate clearly?
• Do they listen to your questions?
• Do you actually like them? If they are difficult to get hold of now, imagine what they will be like when you need to ask a difficult question later.

Summary

Choosing a builder is an investment of time. Do not rush it. Check their past work, get a detailed contract, and trust your gut.

Need drawings to get accurate quotes? Builders cannot give you a firm price without clear plans. At Plan My Extension, we produce the technical drawings builders need to give you an accurate, fixed quote. Get your quote started today.