Hertfordshire
Rear extensions in Croxley Green
Rear extensions in Croxley Green: single-storey and two-storey extensions, side returns, wraparounds and glass-led designs, planned around Victorian terraces and 1930s semis and the English rules.
Croxley Green is in Hertfordshire, with postcode districts including WD1, WD3 and WD18. The nearest places we also cover are Batchworth (0.6 miles) and Rickmansworth (1.2 miles).
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Rear extensions we build in Croxley Green
- 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 Hertfordshire:
- 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 Croxley Green
East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Example | Guide inc VAT |
|---|---|
| Single-storey, 3 m × 4 m (12 m²) | £24,000–£39,500 |
| Single-storey, 4 m × 6 m (24 m²) | £48,500–£79,000 |
| Two-storey, 3 m × 5 m footprint (30 m²) | £57,000–£86,000 |
| Side return, about 14 m² | £34,000–£56,500 |
| Wraparound, about 25 m² | £58,500–£95,500 |
What are homes in Croxley Green like to extend?
Croxley Green mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
Planning rules for Croxley Green
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.
Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.
Nearby towns
FAQ
Questions people ask
How much is a rear extension in Croxley Green?
A 3 m × 4 m single-storey rear extension is about £24,000–£39,500 including VAT at our East of England guide rates; the written price follows a survey.
Do I need planning permission in Croxley Green?
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 Croxley Green 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.