Golders Green, Greater London
Semi-detached rear extension in Golders Green
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Golders Green and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Golders Green and its postcode districts NW2, NW4 and NW11 are part of our Greater London coverage. Where a Golders Green semi already has a small lean-to at the back, we usually replace it rather than extend it.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a semi-detached rear extension cost in Golders Green?
In Golders Green, our guide for a semi-detached rear extension is £2,470–£4,030 per square metre including VAT for a standard specification. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £29,500–£48,500 |
| 4 m wide × 5 m deep (20 m²) | £49,500–£80,500 |
| 4 m wide × 6 m deep (24 m²) | £59,500–£96,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a semi-detached rear extension in Golders Green?
Planning for a semi-detached rear extension in Golders Green follows the English householder rules.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Golders Green like to extend?
Much of Golders Green is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.
How a semi-detached rear extension in Golders Green comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Golders Green
Neighbouring places we cover include Cricklewood (1.5 miles) and Kilburn (1.7 miles).
- Semi-detached rear extension in Cricklewood
- Semi-detached rear extension in Kilburn
- Semi-detached rear extension in Finchley
- Semi-detached rear extension in Highgate
- Semi-detached rear extension in Belsize Park
Other work in Golders Green:
FAQ
Semi-detached rear extension questions in Golders Green
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Do I need planning permission for a rear extension in Golders Green?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
Do you handle building control in Golders Green?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Is the site visit in Golders Green free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.