Extending your home in Winchester
Looking to extend your home in Winchester? Start here: extension types, guide prices for Winchester, the planning rules that apply and how a project runs.
- Postcode districtsSO21, SO22, SO23
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Winchester and surrounding towns
Site visits are available across Winchester (SO21, SO22, SO23). Nearby, we also take on projects in Eastleigh (7 miles), Southampton (12 miles), Totton (13 miles), Andover (13 miles), Hythe (15 miles). For homes towards Wiltshire, Salisbury is around 21 miles away.
Do extensions in Winchester need planning permission?
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.
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).
Choosing the right extension in Winchester
The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
Start by comparing single-storey rear extensions, orangery extensions and wraparound extensions: between them they cover most of the layouts we see requested for houses like these.
What extensions cost in Winchester
Every figure below is a guide for Winchester, adjusted for South East England build costs (×1.12) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
Every extension type in Winchester
- Side return extensions · from £20,000
- Glass box extensions · from £33,500
- Porch extensions · from £4,450
- Conservatory replacement extensions · from £22,000
- Double-storey extensions · from £42,500
- Building regulations for extensions · from £1,000
- Bungalow extensions · from £29,000
- Kitchen extensions · from £30,000
- Orangery extensions · from £33,500
- Bedroom extensions · from £29,000
- Home office extensions · from £17,500
- Flat roof extensions · from £23,500
- Single-storey rear extensions · from £23,500
- Annexe extensions · from £61,500
- Side extensions · from £24,500
- Timber frame extensions · from £23,500
- Extension plans and drawings · from £1,300
- Pitched roof extensions · from £24,500
- Extensions over a garage · from £26,500
- Planning permission for extensions · from £350
- Utility and boot room extensions · from £15,500
- Wraparound extensions · from £40,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions about extensions in Winchester
How much does an extension cost in Winchester?
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 Winchester?
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.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Winchester, and the guide-price tool gives a range for your own size and finish in about a minute.
Do you cover all of Winchester?
Yes, including the surrounding parts of Hampshire. Site visits are free and there is no obligation.
Book a free site visit in Winchester
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.