Blackheath, Greater London
Glazed rear extension in Blackheath
For homes in Blackheath, 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.
Blackheath and its postcode districts SE3, SE10 and SE13 are part of our Greater London coverage. If your garden in Blackheath 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 Blackheath?
In Blackheath, 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 Blackheath?
Here is how the rules in England apply to a glazed rear extension in Blackheath.
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 Blackheath like to extend?
Much of Blackheath 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 Blackheath 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.
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.
Glazed rear extensions near Blackheath
Neighbouring places we cover include Lee (0.6 miles) and Kidbrooke (0.8 miles).
- Glazed rear extension in Lee
- Glazed rear extension in Kidbrooke
- Glazed rear extension in Greenwich
- Glazed rear extension in Ladywell
- Glazed rear extension in Catford
Other work in Blackheath:
FAQ
Glazed rear extension questions in Blackheath
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.
How much does a glazed rear extension cost in Blackheath?
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.
Is there a limit on how much glass I can have?
In England the simple rule is 25% of the floor area plus openings removed; more is allowed with a calculation showing the house still meets Part L.
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.
How long does a rear extension take to build in Blackheath?
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 you match the brick or stone on my Blackheath house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.