Crystal Palace, Greater London
Two-storey rear extension in Crystal Palace
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. If you live in Crystal Palace and want to know what a two-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Crystal Palace (SE19, SE20 and SE26) as part of our Greater London work. In Greater London we check the neighbours' rear windows first, because the upper floor is where most two-storey schemes win or lose planning.
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 two-storey rear extension cost in Crystal Palace?
Guide prices for a two-storey rear extension in Crystal Palace start from our London rate of £2,340–£3,510 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.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £70,000–£105,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £112,500–£168,500 |
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 two-storey rear extension in Crystal Palace?
Here is how the rules in England apply to a two-storey rear extension in Crystal Palace.
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.
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 Crystal Palace like to extend?
Period terraces in Crystal Palace sit alongside flats, and the difference matters: houses usually keep permitted development rights, while flats and maisonettes need planning permission for any rear extension.
How a two-storey rear extension in Crystal Palace comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
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.
Two-storey rear extensions near Crystal Palace
We also build two-storey rear extensions in nearby Upper Norwood (0.7 miles) and Gipsy Hill (0.8 miles).
- Two-storey rear extension in Upper Norwood
- Two-storey rear extension in Gipsy Hill
- Two-storey rear extension in South Norwood
- Two-storey rear extension in Norbury
- Two-storey rear extension in Thornton Heath
Other work in Crystal Palace:
FAQ
Two-storey rear extension questions in Crystal Palace
How long does a rear extension take to build in Crystal Palace?
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.
What is the 45-degree rule?
Many councils check that a two-storey extension does not cross a 45-degree line drawn from the nearest habitable window of the neighbouring house. We test it at the first drawing.
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.
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 I need planning permission for a rear extension in Crystal Palace?
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.