Kent
Rear extensions in Tonbridge
Rear extensions in Tonbridge: single-storey and two-storey extensions, side returns, wraparounds and glass-led designs, planned around inter-war semis and 1960s estates and the English rules.
Tonbridge is in Kent, with postcode districts including TN9, TN10 and TN11. The nearest places we also cover are Royal Tunbridge Wells (4.3 miles) and Sevenoaks (6.5 miles).
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
Rear extensions we build in Tonbridge
- 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 Kent:
- 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 Tonbridge
South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Example | Guide inc VAT |
|---|---|
| Single-storey, 3 m × 4 m (12 m²) | £25,500–£41,500 |
| Single-storey, 4 m × 6 m (24 m²) | £51,000–£83,500 |
| Two-storey, 3 m × 5 m footprint (30 m²) | £60,500–£90,500 |
| Side return, about 14 m² | £36,000–£59,500 |
| Wraparound, about 25 m² | £61,500–£101,000 |
What are homes in Tonbridge like to extend?
Around Tonbridge the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.
Planning rules for Tonbridge
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 Tonbridge?
A 3 m × 4 m single-storey rear extension is about £25,500–£41,500 including VAT at our South East England guide rates; the written price follows a survey.
Do I need planning permission in Tonbridge?
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 Tonbridge 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.