Northwood, Greater London
Rear extension planning drawings in Northwood
For homes in Northwood, a rear extension is often the simplest way to gain space without moving. Measured survey, design options, planning drawings and the application, handled for you. We take it from survey to completion certificate.
Northwood and its postcode districts HA4, HA5 and HA6 are part of our Greater London coverage. For Northwood homes we start with a measured survey, then draw options before anything is submitted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
What do rear extension planning drawings cost in Northwood?
As a guide, £1,000–£2,500 including VAT for a single-storey rear extension, or £2,000–£3,500 for a two-storey scheme. A householder planning application in England costs £548 (£575 for applications made from 8 December 2026), and a lawful development certificate for proposed work costs half the householder fee. 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 rear extension in Northwood?
Whether your 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.
Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.
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 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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
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.
Rear extension planning drawings near Northwood
Neighbouring places we cover include Northwood Hills (1.1 miles) and Croxley Green (1.9 miles).
- Rear extension planning drawings in Northwood Hills
- Rear extension planning drawings in Croxley Green
- Rear extension planning drawings in Pinner
- Rear extension planning drawings in Batchworth
- Rear extension planning drawings in Ruislip
Other work in Northwood:
FAQ
Rear extension planning drawings questions in Northwood
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.
Do I need planning permission for a rear extension in Northwood?
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.
Do I need an architect?
You need accurate drawings by someone who knows householder planning; we provide them.
What postcode areas do you cover around Northwood?
Including HA4, HA5 and HA6, and the surrounding Greater London area.
How long does a rear extension take to build in Northwood?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
What do rear extension planning drawings cost in Northwood?
As a guide, £1,000–£2,500 including VAT for a single-storey rear extension and £2,000–£3,500 for a two-storey scheme, covering the measured survey, design options and the application. The council fee is extra.