Side extensions for homes in Washington
Our design and build teams take on side extensions in Washington, from the first measured survey through planning and building control to the finished room.
- Guide price in WashingtonFrom £20,000 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsDH4, NE9, NE10, NE37, NE38
How much does a side extension cost in Washington?
These guide figures apply our North East England adjustment (×0.91) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Washington: £1,590 to £3,090 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £20,000 – £24,500 | £22,000 – £29,000 | £28,000 – £37,500 |
| 3 m × 6 m 18 m² | £28,500 – £34,500 | £33,500 – £43,500 | £42,500 – £56,000 |
| 3 m × 8 m 24 m² | £38,000 – £46,000 | £44,500 – £58,000 | £56,500 – £74,500 |
For a figure based on your own dimensions, use our guide-price tool.
Who a side extension suits
- Detached and semi-detached houses with side land
- Homes needing a utility, study or ground-floor bedroom
- Houses where the rear garden is small
Working in Washington
Postcode districts we cover around Washington include DH4, NE9, NE10, NE37, NE38, SR4. We also work in nearby Felling (4 miles), Houghton-le-Spring (5 miles), Hebburn (5 miles), Sunderland (5 miles).
Just over the County Durham border, Chester-le-Street is about 4 miles away. The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
Planning and approvals in Washington
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.
The planning position for a specific Washington address depends on its history and any designations, which is why we check it at the first visit.
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.
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).
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
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 produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about a side extension in Washington
Do I need building regulations approval in Washington?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Washington be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do you cover all of Washington?
Yes. We cover Washington and the surrounding parts of Tyne and Wear. Site visits are free and there is no obligation.
Can I build a side extension without planning permission?
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 planning application.
How close to the boundary can I build?
It depends on height. In England, within 2 m of a boundary the eaves must not exceed 3 m under permitted development. Building on the boundary is possible but brings party wall and maintenance access issues we plan for.
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.