How to Choose a Builder in London: 10 Questions to Ask

1. Are You Accredited?

Look for builders with recognised accreditations: CHAS (Contractors Health and Safety Assessment Scheme) or Constructionline.

Accreditations require vetting, insurance checks, and adherence to codes of practice. They provide reassurance and often access to dispute resolution schemes.

2. Can You Provide References?

Ask for references from similar projects completed in the last 12 to 18 months. Contact previous clients and ask about quality, communication, timeline adherence, and whether they'd use the builder again.

We're happy to provide references and have numerous five star reviews on Checkatrade, Trustatrader, and Google.

3. What Insurance Do You Have?

Builders should have Public Liability Insurance of at least £2 million, and ideally £5 to £10 million, plus Employer's Liability Insurance if they employ anyone.

Ask to see certificates and verify they're current. Never use a builder without proper insurance.

4. Do You Provide Fixed Price Contracts?

Fixed price contracts protect you from cost overruns. The contract should include detailed specifications, payment schedule, timeline with completion date, and procedures for variations.

Avoid builders who only provide vague estimates or resist written contracts.

5. Who Will Be On Site?

Ask whether the builder uses direct employees or subcontractors. Both can work well, but you need to know who's responsible for quality and whether workers are properly supervised.

A dedicated site manager should oversee your project with daily presence and weekly progress reports.

6. What's Your Payment Schedule?

Reasonable payment schedules are staged against completed work. Typical: 10 to 20% deposit, then stage payments (groundworks, structure, first fix, second fix, completion).

Avoid builders demanding large upfront payments. Anything above a 25% deposit is a red flag. Never pay cash. Always use traceable methods.

7. What Warranty Do You Offer?

Structural work should come with a written warranty that is clear, transferable where relevant, and backed by proper documentation. We provide a 15 year structural warranty backed by insurance.

Get warranty terms in writing. Understand what's covered, claim procedures, and whether it's transferable if you sell.

8. How Do You Handle Variations?

Changes during construction are common. The contract should specify how variations are priced, approved in writing before work starts, and added to the contract sum.

Avoid builders who do verbal variations or add costs without prior approval.

9. What's Your Timeline?

Ask for a detailed programme showing key milestones and completion date. Experienced builders provide realistic timelines with contingency for weather and unforeseen issues.

We commit to fixed completion dates in our contracts with compensation discussions if we're late through our fault.

10. How Do You Communicate?

Clear communication is essential. Ask about update frequency (weekly reports are standard), who your main contact is, and response times for queries.

We provide weekly written progress reports with photos and maintain open lines for urgent matters.

Warning Signs to Watch For

Be careful of a builder who asks for a large deposit before any work starts, will not put the price and scope in a written contract, cannot show proof of public liability insurance, or offers a discount for paying in cash. Pressure to decide on the day of a visit is another sign to slow down.

A reputable builder will be happy for you to take your time, will explain what each stage will cost, and will agree a payment schedule linked to completed stages of work rather than dates.

How to Check a Builder Before You Sign

Look up a limited company on Companies House to see when it was registered, who the directors are and whether accounts have been filed. Ask for recent references and, if possible, visit a finished or current job. Read reviews on several independent platforms, including the less glowing ones, and notice how the builder responded.

Ask to see the insurance certificate and the structural warranty details in writing, and confirm what is covered, for how long, and who to contact if something goes wrong after completion.

Next Steps

Brits Construction Services Ltd has been established since 2011 and we are happy to answer all ten of these questions. Call 020 4569 0526 or visit our contact page to arrange a visit.