Extensions in Feltham: design, planning and build
From a small utility to a two-storey addition, we take on house extensions throughout Feltham, starting with a free visit and a planning check.
- Postcode districtsTW3, TW4, TW6, TW12, TW13, TW14
- Price regionLondon (×1.3)
- Planning rulesEngland
- Site visitFree, no obligation
Planning and building control in Feltham
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Feltham and nearby
Site visits are available across Feltham (TW3, TW4, TW6, TW12, TW13, TW14). Nearby, we also take on projects in Hanworth (2 miles), Hounslow (3 miles), Hampton (3 miles), Heston (3 miles), Isleworth (4 miles). Ashford, Surrey, in Surrey, is roughly 2 miles from Feltham and also on our list.
Guide prices for Feltham
We publish guide prices so you can budget before anyone visits. For Feltham they are adjusted by ×1.3, the factor we use across London.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Conservatory replacement extensions | 14 m² | £39,000 – £50,500 |
| Wraparound extensions | 25 m² | £74,500 – £94,500 |
| Extensions over a garage | 12 m² | £32,500 – £42,500 |
| Single-storey rear extensions | 20 m² | £53,000 – £68,000 |
| Double-storey extensions | 32 m² | £74,500 – £98,000 |
| Kitchen extensions | 20 m² | £54,500 – £69,000 |
| Side return extensions | 11 m² | £34,000 – £43,000 |
Choosing the right extension in Feltham
Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
The types we would usually look at first for a home in Feltham are wraparound extensions, glass box extensions and side return extensions, depending on the garden and how the house is laid out.
Extension types and starting prices
- Side return extensions · from £23,000
- Bedroom extensions · from £33,500
- Double-storey extensions · from £49,000
- Building regulations for extensions · from £1,150
- Pitched roof extensions · from £28,500
- Planning permission for extensions · from £450
- Home office extensions · from £20,500
- Porch extensions · from £5,200
- Utility and boot room extensions · from £18,000
- Wraparound extensions · from £46,500
- Annexe extensions · from £71,500
- Flat roof extensions · from £27,000
- Conservatory replacement extensions · from £26,000
- Single-storey rear extensions · from £27,000
- Side extensions · from £28,500
- Extension plans and drawings · from £1,550
- Timber frame extensions · from £27,000
- Extensions over a garage · from £31,000
- Bungalow extensions · from £34,000
- Orangery extensions · from £39,000
- Glass box extensions · from £39,000
- Kitchen extensions · from £35,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Feltham
How much does an extension cost in Feltham?
Using our London factor (×1.3), a standard-spec single-storey extension of 20 m² is a guide £53,000 to £68,000 including VAT, and a 32 m² two-storey extension £74,500 to £98,000. Your written price follows the survey.
How long does an extension take in Feltham?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do I need planning permission for an extension in Feltham?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Book a free site visit in Feltham
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.