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.
Chadderton sits within our coverage for a double-storey extension, as do neighbouring Oldham, Royton and Middleton. 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 West is £57,000–£114,000 including VAT, and your written quote will spell out exactly what that covers.
- Guide price
- £57,000–£114,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- M24, OL1, OL2, OL8 and OL9
- Planning rules
- England
- Local area
- Oldham
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Chadderton?
In Chadderton, guide figures for a double-storey extension sit at £57,000–£114,000, VAT included. We set them using rates for the North West, currently about 5% below the national guide. The table shows what pushes a project towards either end of the range; your own price is set after a free survey.
| Type of job | What it usually involves | Guide in Chadderton |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,000–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £57,000–£114,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £95,000–£171,000 |
The main things that change the figure:
- 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
Scope of the work
- 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
- Electrics, plumbing and heating by qualified trades, with certificates
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Local housing and a double-storey extension
Rows of Victorian red-brick terraces fill much of Manchester, Salford and the mill towns, with stone terraces in the Pennine fringes around Oldham and Saddleworth. South Manchester has Edwardian semis and villas, Wythenshawe was built as a large interwar garden suburb, and city-centre apartments and new estates continue to grow.
Two-up two-down terraces commonly suit loft conversions, kitchen extensions and kitchen refits. Many need repointing and roof work, while semis in the suburbs often take side extensions, driveways and replacement windows.
None of this holds for every street in Chadderton, which is why we look at your actual house before pricing a double-storey extension rather than assuming from its age alone.
Planning and building rules in Chadderton
As Chadderton is in England, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
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
A visit to your home
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a double-storey extension.
Your fixed price
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
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 Chadderton property.
Build and hand over
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Common questions
Can we live at home while it is built?
Most families stay at home during a double-storey extension. The new structure is built outside first, and we only break through into the existing rooms near the end, usually one floor at a time. Upstairs, this may mean a bedroom is out of use for a week or two. We fit dust screens, protect floors and stairs, and plan any time without water or power in advance.
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.
Is a double-storey extension better value than single-storey?
A double-storey extension usually gives better value per square metre than a single-storey one, because the same foundations and roof serve twice the floor area. The overall cost is higher, and planning can be harder because of the effect on neighbours. If you might want an extra bedroom later, building both floors now avoids a second round of disruption and scaffolding.
Do you cover Oldham, Royton and Middleton?
Yes. As well as Chadderton, we cover Oldham, Royton and Middleton and the rest of Greater Manchester. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
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.
Also covering areas around Chadderton
Chadderton and its M24, OL1, OL2 and OL8 postcodes are part of our coverage. Homeowners in Oldham, Royton and Middleton can also book a free survey with us and receive a written price for their job.