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.
From Peterborough, Cambridge, Wisbech and St Neots to the quieter corners of Cambridgeshire, homeowners can book a free survey for a double-storey extension. We look at the building, agree the scope, then send a quote in writing that fixes the cost of that scope. Work follows the rules for England, and our published range for the East of England, £63,000–£126,000 with VAT, gives you a sense of budget before we visit.
- 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
- 8
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Cambridgeshire?
These are guide costs, not quotes. For a double-storey extension in Cambridgeshire the range is £63,000–£126,000, VAT included, reflecting prices in the East of England that are about 5% above the national guide. Once we have visited for a free survey, you get a firm figure for the scope you approve.
| Type of job | What it usually involves | Guide in Cambridgeshire |
|---|---|---|
| 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 |
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
What do you get?
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- First-floor joists, stud walls and new openings upstairs
- Scaffolding for the full build, erected and inspected
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Housing across Cambridgeshire
Cambridge has many Victorian terraces in pale gault brick, with Edwardian villas and modern estates around the city. Peterborough expanded as a new town from the 1970s, adding large planned estates, while Ely, Huntingdon, St Neots and the Fenland market towns keep Georgian and Victorian centres. Limestone appears in villages near the Northamptonshire border.
Narrow terraces commonly suit loft conversions and kitchen extensions. Newer estate homes often need garage conversions, porches and landscaping, and older brick and stone buildings may call for lime-based repointing and carefully specified windows.
This is one of the driest parts of the UK, but open fenland is windy and peat or clay ground can shrink, affecting foundations.
Planning and building rules in Cambridgeshire
As Cambridgeshire 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
Survey and measure
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a double-storey extension, and photograph or measure anything the quote needs to reflect.
Your fixed price
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Getting ready
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 Cambridgeshire 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.
What you can expect from us
Questions about a double-storey extension in Cambridgeshire
How much does a double-storey extension cost?
A typical double-storey extension of 30–40m² across both floors costs £63,000–£126,000, built to a plastered finish. As a rough guide, allow around £1,400–£2,600 per square metre plus fixed costs for groundworks, scaffolding and fees. The second storey usually costs less per square metre than the first, because foundations and roof are shared. Bathrooms upstairs and a complex roof add most. We confirm a fixed price after the survey.
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.
Do you cover Peterborough, Cambridge and Wisbech?
Yes. As well as Cambridgeshire, we cover Peterborough, Cambridge and Wisbech and the rest of Cambridgeshire. 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.
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.
How much will a double-storey extension cost in Cambridgeshire?
As a guide, expect to pay £63,000–£126,000 including VAT for a double-storey extension in Cambridgeshire. That range is adjusted for the East of England, which runs about 5% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Towns in Cambridgeshire
Below is our list of Cambridgeshire towns for a double-storey extension. If yours isn't shown, we may still cover it, so it is worth asking us directly.