extension build in Bath
Single-storey, double-storey, side-return, and wraparound house extensions across Bath (BA1 and BA2) and the surrounding villages. Full project management from planning to plaster.
House extensions in Bath, Trowbridge and across BANES — from a side-return on a terraced street to a double-storey rear build. We handle planning drawings, structural steel, groundworks and Building Control in one fixed-price contract, so the number you sign is the number you pay. Single-storey builds typically run 10–14 weeks; double-storey 16–24 weeks — both confirmed at quote, not discovered mid-build.
The extension build work we take on across Bath — every project, every property type.
Single-storey rear extensions
Double-storey side extensions
Side-return extensions for terraced Bath homes
Wraparound extensions combining rear and side
Kitchen extensions with open-plan living
Conservatory and orangery builds
Garden rooms and outbuildings
Two-storey extensions with structural steel
Recent work
Real jobs, photographed as we finished them. No stock photography.
If any of these sound like your property, it's worth booking a free site visit.
Builders who quote cheap and re-quote after the concrete goes in — fixed price from day one
Planning permission surprises — we flag conservation-area and planning constraints at the site visit
Extensions that ignore the existing house — matching brick, rooflines and levels
No party wall paperwork — we handle notices and surveyors
Structural steel bought as an afterthought — RSJs come with proper calcs
Site chaos for months — scheduled trades, daily tidy, one timeline
We've completed hundreds of extension build projects across Bath. Here's what makes them last.
Single-storey from ~£60,000; double-storey £90,000–£150,000+ (measured Bath ranges)
Planning drawings, submission and party wall notices managed for you
10–14 weeks single-storey, 16–24 double-storey — confirmed in the quote
RSJ / steel installation with structural calcs and Building Control sign-off
Conservation-area and listed-adjacent sites handled — pre-apps where needed
Kitchen extensions with open-plan structure built for the layout you want
200+ projects across Bath and BANES in James's 22 years in the trade
Every extension build project follows the same 8-12 step process. Here's what to expect from your free site visit to your 12-month aftercare check.
James visits your the build property to scope the work, discuss options, and assess constraints — listed status, party walls, ground conditions. No charge, no obligation.
You receive a fully itemised quote — materials, labour, waste removal, sign-off fees all broken down. What we quote is what you pay.
We agree start dates and working hours, order materials, arrange skips and scaffolding where needed, and protect your home with dust sheets and floor coverings.
The crew carries out the work to the agreed spec. Daily tidy-ups and protected access routes — your home stays liveable.
Where the work is structural, Building Control inspects at the required stages and you receive full certification on completion.
James walks the finished work with you. Any snags are dealt with immediately — we only sign off when you are fully satisfied.
You get certificates, warranties and any FENSA/Building Control paperwork, plus guidance on caring for the new work.
If anything needs attention later, we come back. Our reputation in Bath is built on long-term relationships, not one-off jobs.
A real job we've completed — the brief, the challenge, how it ran, and the photographs from site.
Verified customer reviews from our extension build installations across Bath.
We had Aspect Builds build an extension for us and we are absolutely delighted with the finished result. From start to finish the team were professional, reliable and a pleasure to have on site. The quality of the build is excellent, everything was kept tidy, and they kept us fully informed throughout. Great communication, fair pricing and a first-class finish. We wouldn't hesitate to recommend Aspect Builds to anyone considering an extension or any other building work.
Everything you need to know about our extension build service.
Costs vary widely depending on size, finish level, structural work, and site conditions. We give you a fixed-price quote after a free site visit, so you know the exact cost before any work starts. No day rates, no open-ended estimates.
Single-storey rear extensions: 10-14 weeks. Double-storey: 16-24 weeks. Wraparound extensions: 20-28 weeks. We provide a detailed programme at quote stage and stick to it.
Most rear extensions under 4m (or 3m on semi-detached) fall under Permitted Development. Bath's conservation area and Article 4 directions affect many properties. We check and handle the full application if needed — typically 8 weeks lead time.
Yes — side-return extensions are a core part of our work in Bath's terraced housing stock. We work on Victorian and Georgian terraces across Widcombe, Oldfield Park, Bear Flat, Larkhall, and Bathwick. Typical 4-6m dig-out, kitchen extension, full structural work.
Yes — double-storey extensions are common in Bath. We handle the structural steel (RSJ), foundations, brickwork, roofing, and all internal fit-out. Typical project takes 16-24 weeks.
We isolate work areas, dust-sheet, clean daily, and respect your space. For larger projects, we can phase the work so you only have one room out of action at a time. Most Bath extension projects are in occupied homes.
£10M+ public liability (AXA-verified). CSCS cardholders, City & Guilds / NVQ qualified. James is MCIOB chartered through the Chartered Institute of Building. All documentation on request.
Yes — heritage Bath stone matching is a core part of our work. We source Bath stone from the same quarries used historically, and our brickwork matches existing mortar profiles, pointing styles, and stone coursing. Conservation-officer liaison included for listed properties.
Customers who book this service often add one of these.
Property in Bath? See extension build in Bath, where most of the work is Georgian and lime-compatible.
All 28 Bath & BANES areas — Bath city neighbourhoods and the wider market towns we cover.
Free site visits across Bath & BANES. Properties outside our standard coverage area can be quoted by arrangement. Listed building consent, conservation area consent and Building Control notification are handled on your behalf where required.
Bath & BANES
Free site visit across Bath and BANES, a fixed written quote within 48 hours, and no pressure either way.
