Hertfordshire
Rear extensions in Hemel Hempstead
We design and build rear extensions for homes in Hemel Hempstead, Hertfordshire, from single-storey kitchen-diners across the back of the house to two-storey extensions that add a bedroom above.
Hemel Hempstead is in Hertfordshire, with postcode districts including HP1, HP2 and HP3. The nearest places we also cover are Abbots Langley (3.6 miles) and Berkhamsted (5.0 miles).
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Rear extensions we build in Hemel Hempstead
- 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 Hemel Hempstead
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 Hemel Hempstead like to extend?
Hemel Hempstead mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
Planning rules for Hemel Hempstead
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres 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 Hemel Hempstead?
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 Hemel Hempstead?
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 Hemel Hempstead 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.