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.
If you are planning a double-storey extension anywhere in Bedfordshire, including Luton, Bedford, Dunstable and Leighton Buzzard, we can visit, measure up and talk through the options. The planning and building regulations we work to are those for England, and we check them for your address before quoting. Prices remain guide figures for the East of England, at £63,000–£126,000 including VAT, until the survey is done.
- Guide price
- £63,000–£126,000 inc VAT
- Time on site
- 14–22 weeks on site
- Planning rules
- England
- Price level
- About 5% above the national guide
- Towns listed
- 6
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Bedfordshire?
No two jobs cost exactly the same, but the ranges below give a fair picture of a double-storey extension in Bedfordshire. Pricing for the East of England runs about 5% above the national guide, and the overall guide is £63,000–£126,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Bedfordshire |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £42,000–£68,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £63,000–£126,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £105,000–£189,000 |
Your price depends mostly on:
- 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
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
Housing across Bedfordshire
Bedfordshire has a long brick-making history, and brick dominates: Victorian terraces in Bedford and Luton, interwar semis, large post-war estates around Luton and Dunstable, and newer developments near Bedford and Biggleswade. Villages in the north of the county keep limestone cottages, with timber framing and thatch scattered across older settlements.
Terraced houses here often benefit from rear extensions, loft rooms and repointing. Interwar and post-war semis commonly suit kitchen extensions, porches and garage conversions, while older village properties may call for lime plastering and sympathetic window replacements.
Bedfordshire is relatively dry, and its clay soils can shrink in long, dry summers, so foundation depth and nearby trees matter for extensions.
Planning and building rules in Bedfordshire
As Bedfordshire 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
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Price and scope agreed
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 Bedfordshire property.
Build and hand over
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
What you can expect from us
Questions about a double-storey extension in Bedfordshire
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.
Do I need planning permission in Bedfordshire?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Bedfordshire 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.
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.
Do I need planning permission for a two-storey extension?
Most two-storey extensions need planning permission, but it depends on the size, height and position, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, a two-storey rear extension can sometimes be built under permitted development if it is no deeper than 3m and at least 7m from the rear boundary. We check what applies before quoting.
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.
Towns in Bedfordshire
These are the towns in Bedfordshire where you can book a free survey for a double-storey extension. Each has its own page with guide prices and coverage details.