Sittingbourne house extensions
From a small utility to a two-storey addition, we take on house extensions throughout Sittingbourne, starting with a free visit and a planning check.
- Postcode districtsME9, ME10
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Choosing the right extension in Sittingbourne
In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
Start by comparing wraparound extensions, orangery extensions and single-storey rear extensions: between them they cover most of the layouts we see requested for houses like these.
Covering Sittingbourne and nearby
Postcode districts we cover around Sittingbourne include ME9, ME10. The same team covers Faversham (7 miles), Gillingham (9 miles), Chatham (9 miles), Rochester (10 miles), Maidstone (11 miles), all within easy reach. Just over the Essex border, Southend-on-Sea is about 14 miles away.
Popular extension prices in Sittingbourne
Prices on this page use our South East England factor of ×1.12, include VAT at 20% and cover the build; your written price follows a survey and agreed drawings.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
Approvals for an extension in Sittingbourne
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 two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
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.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
All extension types we build in Sittingbourne
- Side extensions · from £24,500
- Single-storey rear extensions · from £23,500
- Wraparound extensions · from £40,000
- Orangery extensions · from £33,500
- Pitched roof extensions · from £24,500
- Porch extensions · from £4,450
- Home office extensions · from £17,500
- Extensions over a garage · from £26,500
- Bungalow extensions · from £29,000
- Glass box extensions · from £33,500
- Extension plans and drawings · from £1,300
- Conservatory replacement extensions · from £22,000
- Utility and boot room extensions · from £15,500
- Planning permission for extensions · from £350
- Timber frame extensions · from £23,500
- Bedroom extensions · from £29,000
- Flat roof extensions · from £23,500
- Side return extensions · from £20,000
- Building regulations for extensions · from £1,000
- Kitchen extensions · from £30,000
- Annexe extensions · from £61,500
- Double-storey extensions · from £42,500
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Sittingbourne
How much does an extension cost in Sittingbourne?
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.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Sittingbourne, and the guide-price tool gives a range for your own size and finish in about a minute.
How long does an extension take in Sittingbourne?
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 I need planning permission for an extension in Sittingbourne?
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 Sittingbourne
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.