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Belmont, Greater London

Glazed rear extension in Belmont

For homes in Belmont, a glazed rear extension is often the simplest way to gain space without moving. Full-height glass, slim frames and big rooflights for the most open rear room. We take it from survey to completion certificate.

Belmont is covered from our Greater London round, including SM1, SM2 and SM3. If your garden in Belmont 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 Belmont?

Guide prices for a glazed rear extension in Belmont start from our London rate of £3,640–£6,240 per square metre, including VAT. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.

Glazed rear extension prices in Belmont
SizeGuide 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

We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.

Do you need planning permission for a glazed rear extension in Belmont?

Here is how the rules in England apply to a glazed rear extension in Belmont.

Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it 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. 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 Belmont like to extend?

Belmont is mostly 1930s semis, short terraces and post-war houses, so full-width single-storey and two-storey rear extensions are realistic on many plots. Some later estates had permitted development rights removed by condition, so we check the planning history first.

How a glazed rear extension in Belmont comes together

  1. Free site visit

    We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.

  2. Drawings and budget

    Floor plans and elevations for the options, each with a guide price.

  3. Paperwork handled

    Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.

  4. 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 Belmont

Close by, we work in Sutton, about 0.5 miles away, and Banstead, about 1.5 miles away.

Other work in Belmont:

All rear extensions in Belmont

FAQ

Glazed rear extension questions in Belmont

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.

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.

Is a glass box a conservatory?

No. It is built to Building Regulations as part of the house, with insulated floor and roof, so it is usable all year.

How long does a rear extension take to build in Belmont?

Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.

Can I live at home while the extension is built?

Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.

Do I need planning permission for a rear extension in Belmont?

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.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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