Belsize Park, Greater London
Side return extension in Belsize Park
For homes in Belsize Park, a side return extension is often the simplest way to gain space without moving. Infilling the narrow passage beside a Victorian or Edwardian back addition. We take it from survey to completion certificate.
Belsize Park and its postcode districts NW3, NW6 and NW8 are part of our Greater London coverage. In Belsize Park 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 Belsize Park?
In Belsize Park, our guide for a side return extension is £2,990–£4,940 per square metre including VAT for a 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 |
|---|---|
| 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 Belsize Park?
Planning for a side return extension in Belsize Park follows the English householder rules.
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 Belsize Park like to extend?
Much of Belsize Park is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.
How a side return extension in Belsize Park 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.
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.
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 Belsize Park
From Belsize Park, the nearest places we also cover are Kilburn (0.9 miles) and Chalk Farm (1.0 miles).
- Side return extension in Kilburn
- Side return extension in Chalk Farm
- Side return extension in Camden Town
- Side return extension in Highgate
- Side return extension in Maida Hill
Other work in Belsize Park:
FAQ
Side return extension questions in Belsize Park
How much does a side return extension cost in Belsize Park?
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.
Do you handle building control in Belsize Park?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Where does the drainage go?
Side passages often carry the soil and rainwater pipes. We survey them first and reroute them under the new floor where needed.
Is the site visit in Belsize Park free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Can you match the brick or stone on my Belsize Park 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 planning permission for a rear extension in Belsize Park?
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.