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.
Chester-le-Street sits within our coverage for a double-storey extension, as do neighbouring Washington, Houghton-Le-Spring and Stanley. Before giving a price we want to see the property: the condition of what's there now, the access, and anything that might need extra work. The guide range for the North East is £54,000–£108,000 including VAT, and your written quote will spell out exactly what that covers.
- Guide price
- £54,000–£108,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- DH2
- Planning rules
- England
- Local area
- County Durham
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Chester-le-Street?
Use the table to gauge the cost of a double-storey extension in Chester-le-Street before we visit. Figures include VAT and are scaled for the North East, coming out about 10% below the national guide, which gives £54,000–£108,000 overall. After a free survey, you receive a fixed written price.
| Type of job | What it usually involves | Guide in Chester-le-Street |
|---|---|---|
| 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 |
Expect these to shape the final quote:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
What do you get?
- Groundworks, foundations and below-ground drainage
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Building in Chester-le-Street
Colliery villages across County Durham are lined with brick and stone terraces, many built for mining families. Durham City has Georgian and Victorian streets, Darlington has Victorian terraces and villas, and Peterlee and Newton Aycliffe were planned as post-war new towns. Dales farmhouses in Weardale and Teesdale are stone, often under stone or slate roofs.
Colliery terraces commonly suit loft rooms, rear extensions and window replacement, and many need repointing. New-town homes often benefit from rendering or cladding upgrades and roofline renewal, while stone farmhouses may need lime work.
If your house in Chester-le-Street fits one of these patterns, it helps us anticipate what a double-storey extension will involve, though we always confirm the details on site.
Permissions for a double-storey extension in Chester-le-Street
Because Chester-le-Street falls under England's rules, the guidance below is the version relevant to you. Before sending a price, we check your property's position with the council.
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.
The four stages
Free site survey
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a double-storey extension so the price reflects your home.
Written quote
After the survey we send a quote for a double-storey extension that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Plan and prepare
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Chester-le-Street property.
The work itself
Our trades complete a double-storey extension while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
How we work
Common questions
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.
Can the new upstairs room have its own bathroom?
A new upstairs room can usually have an en-suite, provided waste pipes can reach the soil stack or a new one can be installed. Running the waste pipe to the right falls is the main design question, and a pumped system is an option where gravity will not work. We plan bathroom positions at the design stage so pipes, ventilation and insulation are built in rather than added later.
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 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.
Do I need planning permission in Chester-le-Street?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Chester-le-Street is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
Nearby towns
Coverage for Chester-le-Street spans DH2. Close by, Washington, Houghton-Le-Spring and Stanley are covered too, and the rest of our UK-wide area follows the same survey-then-quote process from start to finish.