Greater London
Rear extensions in East Barnet
Rear extensions in East Barnet: single-storey and two-storey extensions, side returns, wraparounds and glass-led designs, planned around inter-war semis and terraces and the English rules.
East Barnet is in Greater London, with postcode districts including EN4, EN5 and N20. The nearest places we also cover are Cockfosters (0.6 miles) and New Barnet (0.6 miles).
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Rear extensions we build in East Barnet
- Single-storey rear extensions
- Two-storey rear extensions
- Kitchen-diner rear extensions
- Side return extensions
- Wraparound extensions
- Glazed and glass-box rear extensions
- Rear extensions for terraced houses
- Rear extensions for semi-detached houses
- Rear extensions for bungalows
- Rear extension plans and planning applications
Also available across Greater London:
- Rear extensions for detached houses
- Flat-roof rear extensions
- Pitched and lean-to roof rear extensions
- Knocking through to a rear extension
- Roof lanterns and rooflights for rear extensions
- Permitted development rear extensions
- Larger home extension prior approval (England)
- Building Regulations for rear extensions
Rear extension prices in East Barnet
London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Example | Guide inc VAT |
|---|---|
| Single-storey, 3 m × 4 m (12 m²) | £29,500–£48,500 |
| Single-storey, 4 m × 6 m (24 m²) | £59,500–£96,500 |
| Two-storey, 3 m × 5 m footprint (30 m²) | £70,000–£105,500 |
| Side return, about 14 m² | £42,000–£69,000 |
| Wraparound, about 25 m² | £71,500–£117,000 |
What are homes in East Barnet like to extend?
Much of East Barnet 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.
Planning rules for East Barnet
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Every rear extension in England needs Building Regulations approval, whether or not planning is needed. You can use the council's building control service or a registered building control approver, by full plans (checked before work, usually within five weeks) or a building notice, and you get a completion certificate at the end.
Nearby towns
FAQ
Questions people ask
How much is a rear extension in East Barnet?
A 3 m × 4 m single-storey rear extension is about £29,500–£48,500 including VAT at our London guide rates; the written price follows a survey.
Do I need planning permission in East Barnet?
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.
Is the site visit in East Barnet free?
Yes, with no obligation.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.