Home extensions in Washington
More space without moving: we plan and build extensions across Washington, with one team for the drawings, the council and the build.
- Postcode districtsDH4, NE9, NE10, NE37, NE38, SR4
- Price regionNorth East England (×0.91)
- Planning rulesEngland
- Site visitFree, no obligation
Do extensions in Washington 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 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).
Choosing the right extension in Washington
Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
For many houses here, single-storey rear extensions, kitchen extensions or double-storey extensions gives the most useful space for the budget.
Areas we cover around Washington
Site visits are available across Washington (DH4, NE9, NE10, NE37, NE38, SR4). Nearby, we also take on projects in Felling (4 miles), Houghton-le-Spring (5 miles), Hebburn (5 miles), Sunderland (5 miles), Gateshead (5 miles). Just over the County Durham border, Chester-le-Street is about 4 miles away.
Washington extension prices at a glance
Prices on this page use our North East England factor of ×0.91, 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) |
|---|---|---|
| Kitchen extensions | 20 m² | £38,000 – £48,500 |
| Conservatory replacement extensions | 14 m² | £27,000 – £35,500 |
| Wraparound extensions | 25 m² | £52,000 – £66,000 |
| Single-storey rear extensions | 20 m² | £37,000 – £47,500 |
| Side return extensions | 11 m² | £24,000 – £30,500 |
Choose an extension type
- Timber frame extensions · from £19,000
- Single-storey rear extensions · from £19,000
- Conservatory replacement extensions · from £18,000
- Bedroom extensions · from £23,500
- Extension plans and drawings · from £1,050
- Porch extensions · from £3,600
- Annexe extensions · from £50,000
- Building regulations for extensions · from £800
- Wraparound extensions · from £32,500
- Side return extensions · from £16,000
- Double-storey extensions · from £34,500
- Planning permission for extensions · from £300
- Pitched roof extensions · from £20,000
- Side extensions · from £20,000
- Home office extensions · from £14,500
- Glass box extensions · from £27,000
- Kitchen extensions · from £24,500
- Orangery extensions · from £27,000
- Extensions over a garage · from £21,500
- Utility and boot room extensions · from £12,500
- Bungalow extensions · from £23,500
- Flat roof extensions · from £19,000
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 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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Washington
How much does an extension cost in Washington?
Using our North East England factor (×0.91), a standard-spec single-storey extension of 20 m² is a guide £37,000 to £47,500 including VAT, and a 32 m² two-storey extension £52,000 to £68,500. Your written price follows the survey.
Do I need planning permission for an extension in Washington?
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.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
How long does an extension take in Washington?
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.
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.
Book a free site visit in Washington
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.