Side return extensions in East Barnet
A side return extension in East Barnet starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in East BarnetFrom £23,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsEN4, EN5, N14, N20
Do I need planning permission in East Barnet?
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
How much does a side return extension cost in East Barnet?
Prices below are for East Barnet, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
Typical rates in East Barnet: £2,730 to £4,940 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £23,000 – £28,000 | £24,500 – £31,500 | £31,000 – £40,000 |
| 2 m × 5.5 m 11 m² | £30,000 – £36,000 | £34,000 – £43,000 | £42,500 – £54,500 |
| 2.2 m × 7 m 15 m² | £40,500 – £49,000 | £46,500 – £58,500 | £58,500 – £74,500 |
For a figure based on your own dimensions, use our guide-price tool.
Is a side return extension right for your house?
- Narrow galley kitchens
- Victorian and Edwardian terraces with a rear outrigger
- Homes where the garden is too small to lose much depth
Local to East Barnet
Postcode districts we cover around East Barnet include EN4, EN5, N14, N20. The same team covers Barnet (2 miles), Friern Barnet (2 miles), Palmers Green (3 miles), Enfield (3 miles), all within easy reach.
Just over the Hertfordshire border, Potters Bar is about 3 miles away. Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about a side return extension in East Barnet
Who do I contract with for a side return extension in East Barnet?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Do you cover all of East Barnet?
Yes. We cover East Barnet and the surrounding parts of Greater London. Site visits are free and there is no obligation.
How long does a side return extension take to build in East Barnet?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Do side return extensions need planning permission?
In England many single-storey side returns fit within permitted development if they stay within the height limits and are no wider than half the width of the original house. Conservation areas, listed buildings and flats need an application. Other UK nations have their own rules, which we check.
How much does a side return extension cost?
Our guide range is about £2,730 to £4,940 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £34,000 to £43,000 at standard spec in East Barnet, more in London.
Book a free site visit in East Barnet
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.