Harrow on the Hill, Greater London
Two-storey rear extension in Harrow on the Hill
Two-storey rear extension in Harrow on the Hill: 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.
Harrow on the Hill and its postcode districts HA1, HA2 and HA3 are part of our Greater London coverage. Two-storey rear extensions suit semi-detached houses in Harrow on the Hill 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 on the Hill?
A two-storey rear extension in Harrow on the Hill is priced at £2,340–£3,510 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a two-storey rear extension in Harrow on the Hill?
Here is how the rules in England apply to a two-storey rear extension in Harrow on the Hill.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
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 on the Hill like to extend?
Much of Harrow on the Hill is 1920s and 1930s semis and short terraces with longer gardens than inner London, which suit full-width single-storey rear extensions. Parking suspensions, skip licences and controlled hours on residential streets shape the programme more than the build itself.
How a two-storey rear extension in Harrow on the Hill 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
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 Harrow on the Hill
Close by, we work in Harrow, about 0.5 miles away, and Sudbury, about 1.2 miles away.
- Two-storey rear extension in Harrow
- Two-storey rear extension in Sudbury
- Two-storey rear extension in Headstone
- Two-storey rear extension in Wealdstone
- Two-storey rear extension in Wembley
Other work in Harrow on the Hill:
FAQ
Two-storey rear extension questions in Harrow on the Hill
What postcode areas do you cover around Harrow on the Hill?
Including HA1, HA2 and HA3, and the surrounding Greater London area.
How long does a rear extension take to build in Harrow on the Hill?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Is two-storey cheaper per square metre than single-storey?
Usually yes, because the foundations and roof are shared across twice the floor area. The total cost is higher.
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 on the Hill house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.