A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
We offer a double-storey extension across Tyne and Wear, and Sunderland is one of the places we cover, along with nearby Seaham, Washington and Houghton-Le-Spring. Before anything is agreed we visit, check the existing structure and talk through your options. You then receive a written quote setting out the full scope; for most homes in the North East it sits within £54,000–£108,000 including VAT.
- Guide price
- £54,000–£108,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- SR1, SR2, SR4, SR5 and SR6
- Planning rules
- England
- Local area
- Tyne and Wear
- Survey
- Free, with a written quote
Double-storey extensions prices in Sunderland
Prices for a double-storey extension vary from house to house, but in Sunderland most projects fall within £54,000–£108,000 including VAT. That reflects costs in the North East, about 10% below the national guide. Treat the table as a budgeting aid; the written figure follows a survey we carry out for free.
| Type of job | What it usually involves | Guide in Sunderland |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £36,000–£58,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £54,000–£108,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £90,000–£162,000 |
What moves the price up or down:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
What do you get?
- Groundworks, foundations and below-ground drainage
- First-floor joists, stud walls and new openings upstairs
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Building in Sunderland
Tyneside flats, pairs of upper and lower flats behind a terraced front, are a distinctive feature of Newcastle and Gateshead. Sunderland is known for its single-storey terraced 'Sunderland cottages', and both cities have Victorian brick and stone terraces, interwar estates and post-war housing. Washington was built as a new town from the 1960s.
Cold North Sea winds and sea frets affect the coast at Tynemouth and South Shields, and former coal workings underlie parts of the area.
None of this holds for every street in Sunderland, which is why we look at your actual house before pricing a double-storey extension rather than assuming from its age alone.
Do you need permission in Sunderland?
Which rules apply depends on where you live. For Sunderland, the answer is England, and the points below reflect that; we verify them with the council before quoting.
In England, a two-storey rear extension can only be permitted development if it is no more than 3 m deep, at least 7 m from the rear boundary and finished to match the house. Most double-storey and all two-storey side extensions need full planning permission.
Building Regulations approval is needed, with structural calculations for beams, foundations and the roof. The Party Wall etc. Act 1996 often applies on semi-detached and terraced houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
What happens after you get in touch?
A visit to your home
A free survey comes first. It gives us what we need to price a double-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Quote in writing
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Booking the work
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
On site to finish
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
Working with SK Home Improvements
Common questions
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Will the extension affect my neighbours?
A double-storey extension can affect neighbours' light, outlook and privacy, which is why planning departments look closely at height, depth and window positions. Side windows facing neighbours often need obscure glass. Work near a shared wall may also need party wall notices; the Party Wall etc. Act 1996 applies in England and Wales only. We talk through these points early so the design is realistic.
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a double-storey extension, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
How is the new roof joined to the existing house?
The new roof is usually tied into the existing roof so the two read as one. On a rear extension this often means a lower ridge or a hipped end, with valleys where the slopes meet. We strip back some existing tiles, fix new rafters and battens, and lay matching tiles or slates. Lead or proprietary flashings seal the junctions so water runs off properly.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
Near Sunderland
Addresses in SR1, SR2, SR4 and SR5 are all covered for Sunderland, along with Seaham, Washington and Houghton-Le-Spring close by. Give us your postcode when you get in touch and we will confirm the details.