Harrow Weald, Greater London
Two-storey rear extension in Harrow Weald
Two-storey rear extension in Harrow Weald: a larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. We measure the house, show you what the rules allow, price it in writing and build it.
We cover Harrow Weald (HA1, HA3 and HA7) as part of our Greater London work. Two-storey rear extensions suit semi-detached houses in Harrow Weald best, where the extra bedroom matters as much as the bigger kitchen.
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 Harrow Weald?
Guide prices for a two-storey rear extension in Harrow Weald 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 Harrow Weald?
Here is how the rules in England apply to a two-storey rear extension in Harrow Weald.
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. 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 Harrow Weald like to extend?
Harrow Weald 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 two-storey rear extension in Harrow Weald 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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.
Two-storey rear extensions near Harrow Weald
From Harrow Weald, the nearest places we also cover are Wealdstone (0.7 miles) and Headstone (1.3 miles).
- Two-storey rear extension in Wealdstone
- Two-storey rear extension in Headstone
- Two-storey rear extension in Harrow
- Two-storey rear extension in Pinner
- Two-storey rear extension in Bushey
Other work in Harrow Weald:
FAQ
Two-storey rear extension questions in Harrow Weald
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
How much does a two-storey rear extension cost in Harrow Weald?
As a guide, £2,340–£3,510 per square metre including VAT for a standard specification. For example, 3 m × 5 m footprint, two floors (30 m²): about £70,000–£105,500 at that rate. Your written price follows the survey.
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.
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.
Can you match the brick or stone on my Harrow Weald house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.