How to Choose a Builder in London: The Expert Guide

Choosing the right builder is arguably the single most important decision in your project. A good builder makes a difficult project bearable; a bad one can turn it into a nightmare. Here is how to vet them properly in London.

The Essential Checks

Never rely on a simple handshake. Before hiring anyone, you must verify:

Trading History: Check Companies House. How long have they been trading? Beware of “phoenix companies” that close and reopen under new names.
Insurance: Ask to see their “Policy Schedule” for Public Liability (minimum £2m, ideally £5m) and Employers’ Liability. Call the insurer to verify it is valid.
Previous Work: Do not just look at photos. Visit a completed project and, crucially, a current site. Is it tidy? Are the workers professional?

Analyzing the Quote

A professional quote should be broken down intricately. Avoid one-page estimates.

Inclusions/Exclusions: Who pays for skip permits? Who supplies the tiles? Is rubbish removal included?
VAT: Is it included?
Payment Schedule: Never pay more than 10-15% upfront. Payments should be tied to valuations of work done (e.g., foundations poured, roof on, first fix).

Contracts are Vital

For any project over £20,000, use a standard building contract like a JCT Homeowner Contract or a FMB Plain English Contract. This protects both parties and clearly sets out:

Start and completion dates
Payment terms
Dispute resolution
Retention (typically 5% held back for 3-6 months to fix snags).

Major Red Flags

“I can do it for cash” (avoid tax) – Illegal and voids your warranty.
“I can start tomorrow” – Good builders are usually booked 3-6 months in advance.
Pressure to sign immediately.
Asking for large upfront payments “for materials”. Good builders have trade accounts.