Bedroom extensions for homes in Finchley
Our design and build teams take on bedroom extensions in Finchley, from the first measured survey through planning and building control to the finished room.
- Guide price in FinchleyFrom £33,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsN2, N3, N12, NW4, NW7
Guide prices for Finchley
For Finchley we adjust our national guide rates by ×1.3, the factor we use for London. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Finchley: £2,080 to £4,160 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £33,500 – £41,500 | £33,500 – £44,000 | £37,000 – £50,000 |
| Bedroom and en-suite 18 m² | £37,000 – £46,000 | £44,000 – £57,500 | £56,000 – £75,000 |
| Two rooms 30 m² | £62,000 – £76,500 | £74,000 – £96,000 | £93,500 – £125,000 |
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in Finchley
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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).
Local to Finchley
We cover Finchley and the postcode districts N2, N3, N12, NW4, NW7, NW11. Nearby, we also take on projects in Golders Green (2 miles), Friern Barnet (2 miles), Muswell Hill (2 miles), Cricklewood (3 miles).
Borehamwood, in Hertfordshire, is roughly 5 miles from Finchley and also on our list. London's housing is dominated by Victorian and Edwardian terraces, many with a rear outrigger and a side return, and 1930s semis in the outer boroughs. Conservation areas are common, so the planning check comes first.
Who a bedroom extension suits
- Homeowners who want an en-suite master bedroom
- Growing families
- Multi-generational households
From first visit to completion
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about bedroom extensions
Do you cover all of Finchley?
Yes. We cover Finchley and the surrounding parts of Greater London. Site visits are free and there is no obligation.
Do I need building regulations approval in Finchley?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How long does a bedroom extension take to build in Finchley?
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.
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.
Book a free site visit in Finchley
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.