Bedroom extensions in Potters Bar: design, approvals and build
If you live in Potters Bar 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 Potters BarFrom £27,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsEN6
Included in a typical project
- Layout options: two-storey, over-garage or ground floor
- En-suite drainage and ventilation design
- Planning drawings and application
- Fire safety: escape windows and smoke alarms to building regulations
How much does a bedroom extension cost in Potters Bar?
These guide figures apply our East of England adjustment (×1.06) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Potters Bar: £1,700 to £3,390 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £27,500 – £34,000 | £27,500 – £36,000 | £30,500 – £41,000 |
| Bedroom and en-suite 18 m² | £30,500 – £37,500 | £36,000 – £47,000 | £45,500 – £61,500 |
| Two rooms 30 m² | £50,500 – £62,500 | £60,000 – £78,000 | £76,000 – £102,000 |
For a figure based on your own dimensions, use our guide-price tool.
Planning rules that apply in Potters Bar
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
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).
Extensions in and around Potters Bar
Across EN6, we can visit, measure and advise. Nearby, we also take on projects in Borehamwood (5 miles), Hatfield (5 miles), Cheshunt (6 miles), Welwyn Garden City (8 miles).
The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
What happens next
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 Potters Bar home, measure up, talk through what you want and check the planning position.
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions people ask about bedroom extensions
Do you cover all of Potters Bar?
Yes. We cover Potters Bar and the surrounding parts of Hertfordshire. Site visits are free and there is no obligation.
How long does a bedroom extension take to build in Potters Bar?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Will my neighbours in Potters Bar 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 much does a bedroom extension cost?
Our guide range is about £1,700 to £3,390 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £36,000 to £47,000 at standard spec, depending on whether it is part of a larger two-storey build.
Will a new bedroom need planning permission?
Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.
Book a free site visit in Potters Bar
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.