Bedroom extensions in Swindon
Thinking about a bedroom extension for your Swindon home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in SwindonFrom £26,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsSN1, SN2, SN3, SN4, SN5
Extensions in and around Swindon
We cover Swindon and the postcode districts SN1, SN2, SN3, SN4, SN5, SN25. We also work in nearby Calne (12 miles), Chippenham (16 miles), Devizes (18 miles), Melksham (20 miles).
Just over the Gloucestershire border, Cirencester is about 14 miles away. In the South West, local stone, render and brick vary from town to town, so matching materials is a big part of designing an extension that looks right.
How much does a bedroom extension cost in Swindon?
These guide figures apply our South West England adjustment (×1.02) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Swindon: £1,630 to £3,260 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £26,500 – £32,500 | £26,500 – £34,500 | £29,000 – £39,500 |
| Bedroom and en-suite 18 m² | £29,000 – £36,000 | £34,500 – £45,000 | £44,000 – £59,000 |
| Two rooms 30 m² | £48,500 – £60,000 | £58,000 – £75,000 | £73,000 – £98,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Planning and approvals in Swindon
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
What we take care of
- Layout options: two-storey, over-garage or ground floor
- Fire safety: escape windows and smoke alarms to building regulations
- Heating extended to the new rooms
- Planning drawings and application
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Swindon home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a bedroom extension in Swindon
Who do I contract with for a bedroom extension in Swindon?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will my neighbours in Swindon be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do you cover all of Swindon?
Yes. We cover Swindon and the surrounding parts of Wiltshire. Site visits are free and there is no obligation.
Will a new bedroom need planning permission?
Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.
How much does a bedroom extension cost?
Our guide range is about £1,630 to £3,260 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £34,500 to £45,000 at standard spec, depending on whether it is part of a larger two-storey build.
Book a free site visit in Swindon
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.