Bedroom extensions across Mangotsfield
If you live in Mangotsfield and want more space without moving, a bedroom extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in MangotsfieldFrom £26,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsBS15, BS16, BS36
How much does a bedroom extension cost in Mangotsfield?
Prices below are for Mangotsfield, using the South West England factor of ×1.02. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Mangotsfield: £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 |
Try the guide-price tool to see a range for your own size and finish.
Planning and approvals in Mangotsfield
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.
The planning position for a specific Mangotsfield address depends on its history and any designations, which is why we check it at the first visit.
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).
Covering Mangotsfield
Postcode districts we cover around Mangotsfield include BS15, BS16, BS36. Neighbouring towns we cover include Kingswood (2 miles), Yate (5 miles), Thornbury (8 miles), Dursley (15 miles).
For homes towards Somerset, Keynsham is around 5 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.
What we take care of
- Fire safety: escape windows and smoke alarms to building regulations
- Heating extended to the new rooms
- Structure, roof, insulation and finish
- Planning drawings and application
- En-suite drainage and ventilation design
- Layout options: two-storey, over-garage or ground floor
New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.
How the project works
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about a bedroom extension in Mangotsfield
Do I need building regulations approval in Mangotsfield?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Mangotsfield 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.
How long does a bedroom extension take to build in Mangotsfield?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
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 Mangotsfield
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.