From £1,950 per m²Kitchen & Rear Extensions
Single and double-storey extensions with bi-folds and roof lights, from foundations to the final coat of paint.
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4.9156 reviews
Builders in Bristol & Bath · FMB member
Extensions and lofts, on time and on budget.
Kitchen extensions, loft conversions and renovations, managed start to finish by one local team. Plans, building regs and a written schedule included.
FMB MemberFederation of Master Builders
TrustMark RegisteredGovernment-endorsed quality scheme
Insurance-Backed Warranty10 years on structural work
Fully Insured£5m public liability
Building Regs HandledPlans and sign-off arranged
0+
Extensions & lofts
0 yrs
In Bristol & Bath
0.0★
Google rating
0%
Finished on schedule
What we build
Every building job, done right and documented.
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From £1,950 per m²
From £45,000Loft Conversions
Dormer and Velux loft conversions with an en-suite, most finished in 6 to 8 weeks.
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Free surveyRenovations
Knock-throughs, steel beams, re-plastering and full house refurbishments, managed by one team.
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Included in quotePlans & Building Regs
We work with local architects and structural engineers, and handle planning and building control for you.
Get a free quoteGuide prices
What a typical project costs.
Guide prices to help you plan. Your fixed quote comes after a free survey, broken down room by room.
Single-Storey Extension
Approx. 25m² kitchen extension
£55,000from
- Foundations to decoration
- Bi-folds and roof lights
- Building regs sign-off
Dormer Loft Conversion
Bedroom + en-suite
£52,000from
- Steels and staircase
- Fire safety and insulation
- 6 to 8 weeks on site
Velux Loft Conversion
No dormer needed
£38,000from
- Roof lights
- Usually no planning needed
- 4 to 6 weeks on site
Knock-Through
Open-plan living
£6,500from
- Structural engineer calcs
- Steel beam fitted
- Plastered and ready to paint
Sample prices for this demo. Your fixed quote is confirmed in writing after a free survey.
4.9 stars from 156 Google reviews
Meet the builder
One builder, one schedule, no disappearing acts.
Everyone has heard a builder horror story: the deposit taken, the job half done, the phone never answered.
We work the opposite way. You get a written schedule, you pay in stages as work is finished, and I’m on site every week to walk you through progress.
— Tom Ashworth
Owner & site manager
- years building in Bristol
- 15
- years building in Bristol
- extensions and lofts
- 320+
- extensions and lofts
- large up-front deposits
- 0
- large up-front deposits
Recent projects
Real jobs from your area. Tap any photo.
Google reviews
Homeowners who stopped worrying about the forecast.
4.9
156 Google reviews
O
Olivia Grant
Bishopston · 2 weeks ago
“Dormer loft with an en-suite, finished a week ahead of the schedule Tom gave us. We paid in stages, so we never felt exposed.”
Loft conversion
How it works
Four steps. No pressure, no surprises.
- 1
Free survey
We visit, listen and tell you honestly what is possible.
- 2
Plans and fixed quote
Drawings, building regs and a room-by-room price.
- 3
Written schedule
Start date, milestones and stage payments agreed.
- 4
Build and hand over
Weekly updates, sign-off certificate and warranty.
Why homeowners choose us
Severn Build vs. the typical firm
| What you get | Severn Build | Others |
|---|---|---|
| Stage payments, no big deposit | ||
| Written schedule with milestones | ||
| FMB member, TrustMark registered | Sometimes | |
| Building regs handled for you | Extra | |
| Weekly photo updates | ||
| Insurance-backed warranty |
Pay in stages as the work is done
No large deposit. You pay at agreed milestones, only for work that is finished and checked.
- Free survey
- Design chat
- Video call
Book your free survey in 30 seconds.
Pick what you need and a time that suits you. A real builder, not a call centre, confirms within 15 minutes.
Find us on Google Maps
Local teams across Bristol & Bath.
Based in Bristol. Free quotes anywhere in our area, usually within 1 to 2 days.
Severn Build & Extend
4.9(156)
Builder
22 Gloucester Road, Bristol, Bristol BS7 8AE
Open · Mon–Fri 7:30am–5:30pm · Sat by appointment
Areas we serve
- Bristol
- Clifton
- Redland
- Bishopston
- Henleaze
- Westbury-on-Trym
- Southville
- Keynsham
- Portishead
- Bath
- Thornbury
- Clevedon
Questions
Straight answers before you call.
How much does an extension cost in Bristol?
Most single-storey rear extensions in Bristol cost £1,950 to £2,800 per square metre, depending on the finish, glazing and groundwork. We give a fixed, room-by-room quote after a free survey.
Do I need planning permission?
Many single-storey extensions and loft conversions fall under permitted development, but not all. We check your house and handle planning or a lawful development certificate if needed.
How much deposit do you take?
No large deposit. You pay in agreed stages as each part of the work is finished, so you never pay ahead of the build.
Don't wait for the next storm.
Good builders book up months ahead. Get your free survey and a clear quote now.