Extra bedroom and en-suite extensions in Washington
An extra bedroom and en-suite extension is one of the most space-efficient ways to add bedrooms and living space to a house in Washington, because the new floors share one set of foundations and one roof.
What we'd confirm first for a project in Washington.
- Postcode districts
- NE37 and NE38
- County / area
- Tyne and Wear, England
- Price region
- North East England
- Guide price
- £50,500–£68,000 (£1,800–£2,430 per m²), plus £5,500–£11,000 for the en-suite
- Approval route
- It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
- Nearest towns
- Chester-le-Street (3.7 miles), The Boldons (3.9 miles), Felling (4.3 miles)
- Distance to Newcastle upon Tyne
- about 6.4 miles
- First visit
- Free, no obligation
About an extra bedroom and en-suite extension
This service suits you if you need another bedroom, or want a main bedroom with its own bathroom, without converting the loft or moving. You get a first-floor layout that connects well to your landing, an en-suite designed for plumbing and ventilation, a useful room downstairs, the approvals your nation needs and the build, managed by us and carried out by vetted teams working under S&K.
We cover postcode districts NE37 and NE38 in and around Washington, along with neighbouring Chester-le-Street, The Boldons and Felling.
What it costs in Washington
Guide prices for extra bedroom and en-suite extensions in North East England are around £1,800–£2,430 per m² of new floor space, including VAT. For a typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that's roughly £50,500–£68,000 (plus £5,500–£11,000 for the en-suite). The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,660–£2,240 per m² | £46,500–£62,500 |
| Standard | £1,800–£2,430 per m² | £50,500–£68,000 |
| Premium | £2,160–£2,920 per m² | £60,500–£81,500 |
Planning and building regulations in Washington
In England, an extra bedroom extension at the rear can be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary. Upper side windows, including en-suite windows, must be obscure-glazed and non-opening below 1.7 m. Side or deeper designs need planning permission, costing £548 (or £575 for applications made from 8 December 2026).
Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.
Design points for Washington homes
Escape window and fire safety
A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and high, and the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs. We design the windows to meet this.
Planning the en-suite
An en-suite needs a route for the soil pipe to the drains, enough fall for waste water and an extract fan to the outside under Part F. Placing it over the ground-floor utility or near an existing drain keeps pipework short and hidden.
How we'd run your project
Understand the brief
At your home in Washington we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Get it approved
Once you're happy with the design we submit it to the council for Washington and deal with any questions from the planning officer.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.
Questions about extra bedroom and en-suite extensions in Washington
Which postcodes do you cover around Washington?
We cover Washington (NE37 and NE38) and nearby places including Chester-le-Street, The Boldons and Felling, plus the rest of Tyne and Wear. The first site visit is free.
Do I need planning permission for an extra bedroom and en-suite extension in Washington?
Washington is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
How much does an extra bedroom and en-suite extension cost in Washington?
Our guide for North East England, which covers Washington, is £1,800–£2,430 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £50,500–£68,000 (plus £5,500–£11,000 for the en-suite). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Does an extra bedroom add value to my house?
It usually does, though not always by the full cost. Nationwide's 2025 research found that adding a double bedroom to a two-bed house was linked to about 13% higher value, and a double bedroom and bathroom on a three-bed, one-bathroom house up to 24%. Local ceiling prices still apply.
Can an en-suite go in a room with no window?
Yes. A shower room without a window is allowed, provided it has a mechanical extract fan to the outside that meets Part F. Many people prefer a window for daylight, but if it faces a neighbour it will usually need obscure glass. We plan the extract route early so the duct is hidden.
Nearby
Other towns near Washington:
Other extensions in Washington
All two-storey extension services in Washington · Extra bedroom and en-suite extensions across Tyne and Wear
Book a free site visit in Washington and we'll tell you what's possible, what approvals you need and what the design stage would cost.