What is a double-storey extension?
A double-storey extension (also called a two-storey extension) adds rooms on both the ground and first floor in one build. It typically gives a larger kitchen or living space downstairs and an extra bedroom or bathroom above.
How much does a double-storey extension cost in Cheltenham?
In Cheltenham, a double-storey extension typically costs £1,700–£2,550 per m² of floor area (both floors), including VAT at 20% (standard rate). For a typical 36 m² project that is roughly £61,000–£92,000. Building costs in the South West are close to the UK average, so the figures for Cheltenham are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (25 m²) | £42,500–£64,000 |
| Typical project (36 m²) | £61,000–£92,000 |
| Larger project (50 m²) | £85,000–£127,500 |
| Rate per m² | £1,700–£2,550 |
Your quote will depend mainly on:
- Brick matching and external finishes
- Roof design and how it joins the existing roof
- Bathrooms or en-suites on the first floor
- Scaffolding and access to the rear
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a double-storey extension in Cheltenham?
The approval route for Cheltenham is set by planning law in England. In England an extension of more than one storey can only be permitted development at the rear, no more than 3 metres deep and at least 7 metres from the rear boundary, with matching materials and any upper side windows obscure-glazed. Most double-storey extensions therefore go through a householder planning application.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
What we take care of:
- Building control sign-off
- Electrics, heating, plumbing and plastering
- Opening up at both levels with steel beams
- Windows, doors and staircase alterations
- Foundations, drainage and scaffolding
- Brick or block walls, floors and a roof tied into the house
How long does it take?
Expect 14 to 20 weeks on site, after planning and building control approval. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Cheltenham
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
Cheltenham sits in Gloucestershire, about 7 miles east of Gloucester. We cover the whole of Cheltenham, including postcodes GL50 and GL52.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about double-storey extensions in Cheltenham
How much does a double-storey extension cost in Cheltenham?
In Cheltenham, a double-storey extension typically costs £1,700–£2,550 per m² of floor area (both floors), including VAT at 20% (standard rate). A typical 36 m² project comes to roughly £61,000–£92,000. Your fixed price depends on the survey and drawings.
What drawings do I need?
Planning drawings for the application, then more detailed building regulations drawings and structural calculations for building control. We prepare both.
Is a double-storey extension cheaper per square metre?
Usually yes. You pay for one set of foundations and one roof but get two floors of space, so the cost per square metre is often lower than a single-storey extension.
How long does a double-storey extension take in Cheltenham?
Typically 14 to 20 weeks on site, after planning and building control approval. Design and approvals beforehand usually take 3 to 4 months.
Will the first floor need a new staircase?
Not normally. The new rooms are reached from the existing landing, though a doorway or short corridor may need to be formed.