Northwood Hills, Greater London
Side return extension in Northwood Hills
Infilling the narrow passage beside a Victorian or Edwardian back addition. If you live in Northwood Hills and want to know what a side return extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Northwood Hills (HA4, HA5 and HA6) as part of our Greater London work. In Northwood Hills we check the boundary line and the neighbour's gutter before drawing a side return, because a few centimetres decide whether the wall goes on or beside the boundary.
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 side return extension cost in Northwood Hills?
Guide prices for a side return extension in Northwood Hills start from our London rate of £2,990–£4,940 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 |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £36,000–£59,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £52,500–£86,500 |
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 side return extension in Northwood Hills?
Here is how the rules in England apply to a side return extension in Northwood Hills.
Side return infills and the side leg of a wraparound are treated as side extensions in England: single-storey, no more than 4 metres high and no wider than half the original house. They are not permitted development in conservation areas, National Parks or National Landscapes, and a joined wraparound often needs a planning application because the side and rear rules apply together.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
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 Northwood Hills like to extend?
Much of Northwood Hills 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 side return extension in Northwood Hills comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
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.
Side return extensions near Northwood Hills
Neighbouring places we cover include Northwood (1.1 miles) and Pinner (1.2 miles).
- Side return extension in Northwood
- Side return extension in Pinner
- Side return extension in Ruislip
- Side return extension in Ruislip Manor
- Side return extension in Ickenham
Other work in Northwood Hills:
FAQ
Side return extension questions in Northwood Hills
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.
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 combine a side return with a rear extension?
Yes; that is a wraparound extension, and it gives the biggest open-plan room a terrace can have.
How much does a side return extension cost in Northwood Hills?
As a guide, £2,990–£4,940 per square metre including VAT for a standard specification. For example, 2 m wide × 6 m deep (12 m²): about £36,000–£59,500 at that rate. Your written price follows the survey.
Is the site visit in Northwood Hills free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
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.