Covering Harrow
We work in Harrow (HA2) and the places around it, including Brent, Wembley and Northolt.
Homes in London
Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.
What is a side return extension?
A side return extension builds over the narrow passage that runs beside the back of many Victorian and Edwardian terraced houses, widening the kitchen or dining room by a metre or two. It is usually combined with a glazed or part-glazed roof so the deeper room still gets daylight.
- Party wall notices and surveyor liaison
- Structural steel to remove the side wall
- Drainage and new gully positions
How much does a side return extension cost in Harrow?
Guide prices for side return extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| Side return extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £3,350 to £3,700 per m² |
| Good specification | £3,700 to £4,150 per m² |
| High specification | £4,150 to £4,550 per m² |
How is a side return extension approved in Harrow?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.
What should I think about before starting?
- Access is often through the house, so we plan deliveries and protect floors.
- Many terraces sit in conservation areas, where side extensions need planning permission.
How does the project run?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Side return extensions: common questions
Does a side return need planning permission?
In England it can be permitted development if it is single storey, no higher than 4 m and no wider than half the original house. Conservation areas are the main exception.
How long does a side return take?
About 10 to 14 weeks on site.
Can you visit a house in Harrow to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Side return extensions near Harrow
- Side return extensions in Brent
- Side return extensions in Wembley
- Side return extensions in Northolt
- Side return extensions in Greenford
Learn more about side return extensions, or see every project we cover in Harrow.