The answer first
A good local builder will show you finished work, have reviews from real customers on independent sites, carry insurance, belong to a trade body or hold trade qualifications, and give you a detailed written quote after visiting the house. They should explain how the job will run, who does each part and how changes are priced. Being local helps because they know the housing types and council processes nearby, but the checks matter more than distance.
Start with past work
Ask for photographs of similar projects and, if possible, addresses you can see from the street. For an extension, look at how the brickwork matches the house, how the roof meets the old wall and how tidy the finish is around windows. Case studies that explain what the client wanted and how it was built are more useful than a gallery of close-ups.
Reviews and references
Read reviews on platforms the builder does not control, and look for detail: named jobs, how problems were handled, whether the site was kept tidy. A builder with a steady record over years is a better sign than a burst of recent reviews. If you can, speak to a past client directly.
Insurance, membership and qualifications
Check the builder has public liability insurance and ask to see it. Trade bodies such as the Federation of Master Builders vet members and set a code of practice. Trade qualifications show skills were formally learned. None of these replaces seeing the work, but a builder who is proud to show them usually has nothing to hide.
The quote
A proper quote is written, itemised by stage in plain words, and says what is not included. It should cover foundations, drainage, structure, roofing, windows, first and second fix, plastering and making good. It should say who handles Building Control, whether a party wall notice is needed and how extras are agreed. Compare quotes line by line rather than by total.
Questions worth asking
Who will be on site each day? Who do I call with a question? What happens if you find something unexpected in the ground? How will you protect the rest of the house? When will you need access to the kitchen, water or electrics? Clear, calm answers are a good sign.
Red flags
Be cautious of a builder who will not put a quote in writing, asks for large sums before work starts, pushes you to decide on the spot, or has no fixed address or verifiable reviews. Door-to-door offers for work you did not ask for are best declined.
Planning and approvals
Ask the builder how planning and Building Regulations will be handled. Many extensions need either a planning application or confirmation that the work is permitted development, and almost all need Building Regulations approval with inspections at key stages. A builder who works locally will know how the council's Building Control team operates and what inspectors look for, and should build to the approved drawings rather than improvising on site. Keep copies of every approval and the completion certificate for when you sell.
About us
D & A Brickwork & Building is a family-run firm based in Bidwell, Dunstable. We have more than 26 years of building experience, our bricklaying is NVQ Level 2 qualified, we are members of the Federation of Master Builders and we are fully insured. Estimates are free and follow a visit to see the job.
You can see our finished work on the gallery and case-study pages and read customer reviews on the reviews page.
Looking nearer home? See our pages for local builders in Harpenden and local builders in Redbourn.
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Questions people ask
Is a small local builder better than a large firm?
Not automatically. Small firms often give more direct contact with the people doing the work, but check past work, reviews and insurance either way.
What should a builder's quote include?
A written description of each stage, the materials, what is excluded, who handles Building Control and how extra work is agreed.
Should I pay a deposit?
Agree payment terms in writing before work starts and be wary of anyone asking for large sums upfront.
How do I check a builder belongs to a trade body?
Most trade bodies, including the Federation of Master Builders, let you search for members on their own websites.