Belsize Park, Greater London
Glazed rear extension in Belsize Park
Glazed rear extension in Belsize Park: full-height glass, slim frames and big rooflights for the most open rear room. We measure the house, show you what the rules allow, price it in writing and build it.
Belsize Park sits in Greater London, with postcode districts including NW3, NW6 and NW8. If your garden in Belsize Park faces south, expect us to talk about overhangs and solar-control glass before frame colours.
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 glazed rear extension cost in Belsize Park?
In Belsize Park, our guide for a glazed rear extension is £3,640–£6,240 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) | £43,500–£75,000 |
| 4 m wide × 6 m deep (24 m²) | £87,500–£150,000 |
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 glazed rear extension in Belsize Park?
Whether your glazed rear extension in Belsize Park needs a planning application depends on its size, your house and any local restrictions.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Belsize Park like to extend?
Much of Belsize Park 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 glazed rear extension in Belsize Park 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Glazed rear extensions near Belsize Park
Neighbouring places we cover include Kilburn (0.9 miles) and Chalk Farm (1.0 miles).
- Glazed rear extension in Kilburn
- Glazed rear extension in Chalk Farm
- Glazed rear extension in Camden Town
- Glazed rear extension in Highgate
- Glazed rear extension in Maida Hill
Other work in Belsize Park:
FAQ
Glazed rear extension questions in Belsize Park
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do you handle building control in Belsize Park?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Will a glass extension be too hot?
Not if it is designed for its orientation, with solar-control glass, shading and ventilation.
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.
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 Belsize Park?
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.