Extension Builder in Westminster
1144 vetted extension builders covering Westminster. Post your job free and compare responses directly - no obligation.
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Building and renovation work in Westminster
Westminster, part of the City of Westminster, is known for grand civic and institutional buildings alongside residential streets, at the historic core of a borough with the highest concentration of listed buildings in London. Its proximity to Westminster Abbey and the Houses of Parliament and good transport links via Westminster station, and the Circle, District and Jubilee lines continue to make it a popular place for homeowners to invest in renovation and extension projects rather than move - keeping steady demand for reliable, quality extension building work in the area.
With the Westminster Abbey and Whitehall conservation areas, part of a UNESCO World Heritage Site covering parts of Westminster, planning and conservation requirements are a real factor in extension building work here - work that would be straightforward elsewhere can need extra care, matching materials, or formal planning consent locally. Homeowners in Westminster increasingly look for tradespeople who understand that local context, rather than a generic, one-size-fits-all quote.
Mkm Building Services
Builder, Electrician, Plumber, Painter & Decorator, Extension Builder, Gas Engineer
NW8 7BB
Get in touchAltair Building
Builder, Electrician, Plumber, Painter & Decorator, Extension Builder, Gas Engineer
W1W 5PF
Get in touchToclint
Builder, Electrician, Plumber, Extension Builder, Gas Engineer, Groundworker
W1W 5PF
Get in touchLansmere Construction
Builder, Electrician, Plumber, Extension Builder, Gas Engineer
W1S 4JL
Get in touchConvera Construction
Builder, Electrician, Plumber, Extension Builder, Gas Engineer
W1W 5PF
Get in touchByld More
Builder, Electrician, Plumber, Carpenter, Extension Builder, Gas Engineer
W1K 5BF
Get in touchWolani Housing Management
Builder, Plumber, Plasterer, Extension Builder, Gas Engineer
W1B 4HB
Get in touchA.g. International Renovations
Builder, Plumber, Extension Builder, Gas Engineer
W1W 5PF
Get in touchA&B Coreflow Construction
Builder, Plumber, Painter & Decorator, Extension Builder, Gas Engineer
W1K 2AA
Get in touchRedworth Construction Services
Builder, Plumber, Extension Builder, Gas Engineer
W1F 0TL
Get in touchLusso Interiors London
Builder, Carpenter, Painter & Decorator, Extension Builder
W1C 2BU
Get in touchAnastasia Jurgelis Interior Design
Builder, Painter & Decorator, Tiler, Extension Builder
SW1A 1LP
Get in touchWayland Commercial Interiors
Builder, Plasterer, Painter & Decorator, Extension Builder
W1W 5PF
Get in touchRussell King & Son
Builder, Electrician, Plumber, Extension Builder, Gas Engineer
W1W 5PF
Get in touchFoxter Properties
Builder, Electrician, Plumber, Extension Builder, Gas Engineer
W1S 1AY
Get in touchWhat to expect from a extension builder in Westminster
Extensions typically need either planning permission or a Lawful Development Certificate confirming permitted development rights, plus building control approval throughout.
As with any trade, it's worth asking to see proof of insurance and relevant qualifications before work starts, checking recent examples of similar jobs, and getting the scope of work agreed in writing - see our guide on questions to ask before hiring below.
Typical project costs in Westminster
How to Choose a Builder in Westminster
A practical checklist for picking a trustworthy builder if you live in Westminster.
Renovating a Period Property in Westminster: What to Know
What makes renovating an older Westminster property different, from foundations to conservation area rules.
Loft Conversion Cost in Westminster: 2026 Price Guide
Typical loft conversion prices in Westminster, from a simple rooflight loft to a full dormer.
Kitchen Extension Planning Permission in Westminster
Do you need planning permission for a kitchen extension in Westminster? Permitted development limits and local conservation area rules explained.
Loft Conversion & Dormer Planning Permission in Westminster
Do you need planning permission for a loft conversion or dormer in Westminster? Roof volume limits, party walls and conservation area rules explained.
Hiring safely in Westminster
A few things worth checking before you agree to any quote:
Frequently asked questions
How much does a extension builder cost in Westminster?
A single-storey extension typically costs from around £1,800 per m² for a standard finish, before architect fees, planning application fees, and building control sign-off - which usually add another £3,000-£8,000. Get a ballpark for your own project with our free extension cost calculator.
How do I know a extension builder in Westminster is trustworthy?
Every builder on builderfinder.uk is manually checked before their profile goes live - we match their photo ID to their face, verify their UK proof of address, and check their trades and insurance. You can also see their reviews and completed jobs on their profile, and look for the Verified badge, or a Companies House Verified badge if they're a limited company.
Do I need planning permission for extension building work in Westminster?
It depends on the specific job, but it's a real question to ask locally: the Westminster Abbey and Whitehall conservation areas, part of a UNESCO World Heritage Site cover parts of Westminster, and work that would be permitted development elsewhere can need formal planning consent here, or need to match existing materials and style. Always check with the City of Westminster's planning department, or ask your builder to confirm before work starts.
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