Home extensions in Swanley
Every type of house extension in Swanley, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsBR8
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Which extension suits a Swanley home?
Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Depending on the plot, wraparound extensions and orangery extensions are often the strongest options, with single-storey rear extensions worth considering where there is room.
What extensions cost in Swanley
Use these Swanley guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
Planning rules in Swanley
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 extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
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).
Where we work near Swanley
Site visits are available across Swanley (BR8). Nearby, we also take on projects in Dartford (4 miles), Sevenoaks (9 miles), Gravesend (9 miles), Strood (13 miles), Rochester (14 miles). For homes towards Greater London, Bexley is around 3 miles away.
Every extension type in Swanley
- Bedroom extensions · from £29,000
- Wraparound extensions · from £40,000
- Glass box extensions · from £33,500
- Utility and boot room extensions · from £15,500
- Pitched roof extensions · from £24,500
- Flat roof extensions · from £23,500
- Extension plans and drawings · from £1,300
- Building regulations for extensions · from £1,000
- Orangery extensions · from £33,500
- Planning permission for extensions · from £350
- Conservatory replacement extensions · from £22,000
- Double-storey extensions · from £42,500
- Timber frame extensions · from £23,500
- Annexe extensions · from £61,500
- Side extensions · from £24,500
- Extensions over a garage · from £26,500
- Kitchen extensions · from £30,000
- Home office extensions · from £17,500
- Bungalow extensions · from £29,000
- Side return extensions · from £20,000
- Porch extensions · from £4,450
- Single-storey rear extensions · from £23,500
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Swanley
How much does an extension cost in Swanley?
Using our South East England factor (×1.12), a standard-spec single-storey extension of 20 m² is a guide £45,500 to £58,500 including VAT, and a 32 m² two-storey extension £64,500 to £84,500. Your written price follows the survey.
Do I need planning permission for an extension in Swanley?
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.
How long does an extension take in Swanley?
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.
Who do I contract with?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Do you cover all of Swanley?
Yes, including the surrounding parts of Kent. Site visits are free and there is no obligation.
Book a free site visit in Swanley
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.