How to Hire a Good Builder in London (And Red Flags to Avoid)

Hiring a builder is a decision about the work, the people entering your home and how the project will be managed. A good first step is to define the job clearly, then compare how each builder understands the same brief. A polished website or low headline figure cannot tell you whether a quote includes the work you expect.

Write down what you want done

List the rooms, changes and finishes you want, with photos, sketches or drawings where useful. Separate items you have chosen from ideas that still need discussion. Note practical details such as access, parking, working hours, protection of occupied rooms, waste removal and who will supply fixtures. The more clearly you describe the job, the easier it is to ask each builder for a comparable response.

If you need design, engineering or another professional service, say so. Ask whether the builder expects you to provide drawings or whether arranging that work is included in the proposal. Be clear about who will check planning or building-regulation questions with the right authority. The scope should not leave responsibility for an approval hidden between trades.

Meet the person who will manage the work

Ask who your day-to-day contact will be, who is expected on site and which work may be carried out by other firms. Ask how changes are recorded and how you will be told about a delay or an issue found after opening up a wall or floor. Notice whether the answers are clear and whether the builder listens to your questions rather than brushing them aside.

Ask to see examples of similar work and, if possible, speak with recent customers. Ask what the project included, what changed during the work and how those changes were handled. A reference is one source of information, not a substitute for checking that the proposed scope fits your property.

If the project includes specialist work, ask who will carry it out and what checks are appropriate for that trade. Do not assume that a general building firm’s name answers every specialist question. For electrical, gas or other regulated work, check the relevant official guidance and any register that applies to that specific task. Avoid relying on a badge without understanding what activity it covers.

Compare written quotes line by line

Ask each builder to respond to the same drawings or written scope. Check that the quote identifies what will be supplied and fitted, what you must buy, how waste is handled and what finishing or making good is included. Make a note of exclusions, provisional choices and assumptions about the condition of the existing building.

Compare the detail, not only the total. Check whether each offer includes protection, preparation, materials, labour, final clean and any relevant certificates or inspections. If a line is unclear, ask for a plain-English explanation. Worcestershire Trading Standards recommends a detailed written quote and references; Dorset Council’s building-control guidance also recommends a clear work description and comparable quotes.

Ask how payment is linked to progress and what evidence you will receive for each stage. Do not pay the entire project price before work begins. If you are unsure about a payment term, cancellation or your consumer rights, speak to Citizens Advice or use GOV.UK’s consumer-protection guidance before signing. This article is a checklist, not legal advice.

Red flags to take seriously

• A builder will not set out the proposed work, exclusions and assumptions in writing.
• You are pressed to decide before you have time to compare the scope or ask questions.
• The quote is much less detailed than the brief, or leaves key items to be sorted later.
• Payment requests are unclear or are not linked to identifiable work or materials.
• References, insurance details or the identity of the people doing specialist work cannot be explained.
• Planning, building-regulation or highway checks are dismissed without asking what your project involves.

One concern on its own does not prove poor work, but unanswered questions are a reason to pause. Ask the builder to clarify the point in writing. If the answer remains vague, compare another proposal rather than filling in the gaps yourself.

Agree how the job will run

Before starting, agree the written scope, drawings, product choices, payment stages, approximate sequence, access arrangements, waste plan and process for changes. Write down who is responsible for contacting Building Control or the local planning authority if a check is needed. Keep a copy of messages and decisions with the quote so both sides can refer to the same agreement.

Ask what the first week will involve, what you need to move or protect, which rooms will be unavailable and who will lock up. Confirm how the builder will report progress and how you should raise a question. A simple communication plan can prevent different assumptions from becoming a project problem.

For building work in London, see Pimi’s renovations service page and send an enquiry through the contact page. A short outline of your home, the work you want and whether you already have drawings helps make the first conversation specific.