Bedroom extensions for homes in Borehamwood
We design and build bedroom extensions for houses in Borehamwood, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in BorehamwoodFrom £27,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsWD6, WD7
What we take care of
- Heating extended to the new rooms
- Fire safety: escape windows and smoke alarms to building regulations
- En-suite drainage and ventilation design
- Layout options: two-storey, over-garage or ground floor
Covering Borehamwood
We cover Borehamwood and the postcode districts WD6, WD7. We also work in nearby Bushey (4 miles), Potters Bar (5 miles), Watford (5 miles), St Albans (7 miles).
Just over the Greater London border, Barnet is about 3 miles away. 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 should I budget for a bedroom extension in Borehamwood?
Labour and material costs vary across the UK, so for Borehamwood we use our East of England factor (×1.06). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Borehamwood: £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 |
Want a range for your exact size? The guide-price tool takes about a minute.
Planning and approvals in Borehamwood
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.
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 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.
Applications are decided by the local planning authority (your district, borough or unitary council).
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Bedroom extension questions answered
Who do I contract with for a bedroom extension in Borehamwood?
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.
How long does a bedroom extension take to build in Borehamwood?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Do I need building regulations approval in Borehamwood?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
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.
Book a free site visit in Borehamwood
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.