Written by Mark Reid,
Trades Editor ·Verified 23 September 2026
Uxbridge throws up a real mix of building work, and that's down to the housing stock as much as anything. You've got the 1930s semis around Hillingdon and Cowley, Victorian terraces near the town centre, and newer developments out towards Ickenham and Harefield. A builder working on a loft conversion in a semi off Belmont Road faces different challenges to one extending a period property near St Andrew's Church, so local experience with the older brick and clay soil around here genuinely counts for something. Ground conditions vary too, with clay soils in parts of the borough that can affect foundations and extensions, so a builder who knows the area tends to price and plan more accurately than one working blind.
The businesses featured here come from public business listings, ranked using review rating and review count as the main factors, with a small lift given to those showing a working website and a contactable phone number. We read each business's homepage to check that building work is genuinely what they focus on, which stops unrelated trades cluttering the page. Listings flagged as permanently closed get removed automatically as part of that process. Where you spot a Trust Verified badge, that particular business has gone through our fuller check, covering trade qualifications and accreditations, public liability insurance, trading history, customer review history and registered company information. Our How We Verify page sets out exactly what that involves. For any business without the badge, those checks haven't been done by us, so it's worth doing them yourself before signing anything.
Before you commit to a builder, ask to see their public liability insurance certificate and check whether they're registered with a trade body such as the Federation of Master Builders. If the job needs building regulations sign-off, such as a loft conversion or a structural wall removal, ask how that's handled and who submits the paperwork. Get at least two or three written quotes so you can compare not just price but what's actually included, since one quote might cover skip hire and waste disposal while another doesn't. Ask for references from recent local jobs too, ideally ones you can go and look at, and always get a written contract that sets out payment stages, start dates and what happens if the job overruns.
How We Select & Rate The Best Builders in Uxbridge
Ranking is driven mainly by review rating and review count pulled from public business listings, with a small lift given to businesses showing a working website and phone number. We check each business's homepage to confirm building work is what they primarily offer, keeping unrelated trades off the page. Listings marked as permanently closed are removed automatically. Businesses displaying a Trust Verified badge have additionally passed our full verification, covering trade qualifications and accreditations, public liability insurance, trading history, customer review history and registered company information; see our How We Verify page for the full list. Other businesses shown here haven't been independently verified by us, and their inclusion isn't an endorsement. Always carry out your own checks before hiring anyone.
Recommended and Featured listings are paid placements, so a business's fee affects whether and where it appears. Every other listing is ranked on rating and review count from third-party business listings. How we rank & verify →
Insight ProBuild Ltd covers the full build cycle, from groundworks and structural alterations through to internal fit-out, for residential and commercial clients in Uxbridge. The company takes on projects of varying scale, coordinating trades across each stage rather than subcontracting individual phases in isolation. That continuity of oversight tends to suit clients undertaking extensions or full refurbishments in the UB8 area.
Rated 5.0 by its customers, Velonia Interiors Ltd is a building firm based in Uxbridge serving the surrounding area. The company undertakes interior construction and refurbishment work for residential and commercial clients. Its postcode, SL9 0PB, places it well for projects across the Chiltern and South Bucks corridor.
Total Services is a building firm operating out of Uxbridge, covering construction and general building work across the surrounding area. The UB9 postcode places them on the outer edge of the borough, giving them close reach into both west London and the neighbouring Home Counties. No rating is currently listed in the directory.
Transparency notice: Recommended and Featured listings are paid placements, so a business's fee affects whether and where it appears. All other listings are ranked by a combined score drawn from ratings and review counts published on third-party business listings, plus basic completeness signals such as a working website and phone. A Trust Verified badge means we have independently checked that business's documents; businesses without it have not been independently verified by us. How we verify →
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It depends heavily on the scope of work. A single-storey rear extension in Uxbridge typically runs from around £1,600 to £2,200 per square metre, so a modest 20 square metre extension could land somewhere between £32,000 and £44,000 once you include a basic kitchen fit. A loft conversion with dormer might cost £45,000 to £65,000 depending on plumbing for an en suite. Smaller jobs like a garden wall rebuild or internal wall removal could be £800 to £3,000. Prices swing based on access, whether scaffolding is needed, and materials specified, so getting two or three quotes for anything beyond small repairs is the sensible approach.
Do I need planning permission for an extension in Uxbridge?
Many single-storey extensions fall under permitted development rights, meaning no formal planning application is needed, but there are limits on size, height and proximity to boundaries. The London Borough of Hillingdon still requires you to check, especially if your property is in a conservation area or is a listed building, which applies to parts of Uxbridge's older streets. It's worth contacting the council's planning department directly or asking your builder to confirm before work starts, since building without permission when it's required can cause problems later, including at resale.
How long does a typical extension or loft conversion take?
A single-storey extension usually takes eight to twelve weeks from breaking ground to a finished, plastered shell, with kitchen fitting adding further time. Loft conversions tend to run ten to fourteen weeks, partly because of structural work to strengthen floor joists and install a dormer or Velux windows. Weather can slow down groundworks and roofing stages, and lead times for materials like structural steel or specific windows can add unexpected delays, so it's worth asking your builder for a realistic programme with some contingency built in rather than the best-case timeline.
Should I use a builder registered with a trade body?
It's generally a good sign. Membership of bodies like the Federation of Master Builders or TrustMark usually means the business has been through some vetting and has access to guarantee schemes, which matters if the builder were ever to go out of business mid-project. It's not a guarantee of quality on its own, but combined with genuine local reviews and photos of completed work, it gives you more confidence than a business with no accreditations and no visible track record at all.
What paperwork should I get before work starts?
Ask for a written quote that itemises materials, labour and any allowances for unforeseen work, plus a payment schedule tied to project stages rather than a large deposit upfront. You'll also want a copy of their public liability insurance certificate, and for structural work, confirmation of how building regulations approval will be handled and who's submitting the application. A simple written contract covering start and finish dates, what happens with delays, and how variations to the work are priced protects both sides if things don't go to plan.
How do I choose between builders on this list?
Start by reading through the reviews for patterns, not just the star rating, since comments about communication and tidiness on site often tell you more than a number. Check whether a business has a Trust Verified badge, and if it doesn't, ask them directly for proof of insurance, trade body membership and examples of recent, similar jobs in Uxbridge or nearby areas like Cowley or Yiewsley. Visit a current or recent job if they'll let you, and always get quotes from at least two or three builders before deciding, comparing what's actually included rather than just the bottom line figure.
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