Northwood, Greater London
Two-storey rear extension in Northwood
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. We design, get the approvals for and build two-storey rear extensions in Northwood and the surrounding area, with one contract from the first survey to building control sign-off.
Northwood is covered from our Greater London round, including HA4, HA5 and HA6. In Northwood, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
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 Northwood?
For Northwood we work from the London rate: £2,340–£3,510 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 × 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 Northwood?
Whether your two-storey rear extension in Northwood needs a planning application depends on its size, your house and any local restrictions.
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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Northwood like to extend?
Much of Northwood 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 Northwood 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.
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.
Two-storey rear extensions near Northwood
Close by, we work in Northwood Hills, about 1.1 miles away, and Croxley Green, about 1.9 miles away.
- Two-storey rear extension in Northwood Hills
- Two-storey rear extension in Croxley Green
- Two-storey rear extension in Pinner
- Two-storey rear extension in Batchworth
- Two-storey rear extension in Ruislip
Other work in Northwood:
FAQ
Two-storey rear extension questions in Northwood
Do you handle building control in Northwood?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
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.
Does a two-storey rear extension need planning permission?
Almost always. England and Northern Ireland allow 3 metres without an application only if at least 7 metres remains to the rear boundary; Wales and Scotland are similar or stricter.
What postcode areas do you cover around Northwood?
Including HA4, HA5 and HA6, and the surrounding Greater London area.
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.
Can you match the brick or stone on my Northwood house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.