Thornton Heath, Greater London
Glazed rear extension in Thornton Heath
We plan and build glazed and glass-box rear extensions for homeowners in Thornton Heath. Full-height glass, slim frames and big rooflights for the most open rear room. Start with a free site visit, then a written price once the design is agreed.
Thornton Heath and its postcode districts CR7, SE19 and SE25 are part of our Greater London coverage. A wide sliding door with one long rooflight, rather than a fully glazed roof, keeps a glass-led extension usable in summer.
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 Thornton Heath?
For Thornton Heath we work from the London rate: £3,640–£6,240 per square metre of new floor, including VAT, 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 Thornton Heath?
Here is how the rules in England apply to a glazed rear extension in Thornton Heath.
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 Thornton Heath like to extend?
Thornton Heath 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 Thornton Heath comes together
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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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.
Glazed rear extensions near Thornton Heath
Neighbouring places we cover include South Norwood (1.0 miles) and Croydon (1.1 miles).
- Glazed rear extension in South Norwood
- Glazed rear extension in Croydon
- Glazed rear extension in Upper Norwood
- Glazed rear extension in Norbury
- Glazed rear extension in Crystal Palace
Other work in Thornton Heath:
FAQ
Glazed rear extension questions in Thornton Heath
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.
How much does a glazed rear extension cost in Thornton Heath?
As a guide, £3,640–£6,240 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £43,500–£75,000 at that rate. Your written price follows the survey.
Can I have a level threshold?
Yes, with a drainage channel outside the doors and the slab set to the patio level.
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.
Can you match the brick or stone on my Thornton Heath house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do you handle building control in Thornton Heath?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.