Extensions over a garage for homes in Washington
From the first sketch to final sign-off, we plan and build over-garage extensions in Washington and the surrounding Tyne and Wear area.
- Guide price in WashingtonFrom £21,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsDH4, NE9, NE10, NE37, NE38
Working in Washington
Postcode districts we cover around Washington include DH4, NE9, NE10, NE37, NE38, SR4. Neighbouring towns we cover include Felling (4 miles), Houghton-le-Spring (5 miles), Hebburn (5 miles), Sunderland (5 miles).
The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
How much does an over-garage extension cost in Washington?
Prices below are for Washington, using the North East England factor of ×0.91. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Washington: £1,640 to £3,090 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £21,500 – £27,000 | £22,500 – £29,500 | £29,000 – £37,500 |
| Over a large single garage 16 m² | £26,000 – £32,500 | £30,500 – £39,500 | £39,000 – £50,000 |
| Over a double garage 24 m² | £39,000 – £48,500 | £45,500 – £59,000 | £58,500 – £74,500 |
Try the guide-price tool to see a range for your own size and finish.
Do I need planning permission in Washington?
In England any side extension over one storey, including a room built over a side garage, needs a householder planning application. The fee is £548 from 1 April 2026 and councils aim to decide within 8 weeks.
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.
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.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
When an over-garage extension makes sense
- Homes where the landing can connect to the new room
- Detached and link-detached houses with an attached garage
- Families needing a bedroom without losing garden
Fitting the new room to the existing landing is the planning puzzle inside the house. We design the connection first, then the roof, so the extension does not end up with awkward steps or a corridor through a bedroom.
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
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.
Your questions about an over-garage extension in Washington
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Washington, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does an over-garage extension take to build in Washington?
On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
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.
Can I keep using the garage during the build?
Usually not for parking. The garage roof is removed and the space below is used for access and props for part of the build.
Does building over a garage need planning permission?
In England and the rest of the UK, adding a storey over a side garage almost always needs a planning application, because two-storey side extensions are outside permitted development.
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.