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 Kingswood?
In Kingswood, 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. Prices in the South West sit near the national average for this kind of work, and the range for Kingswood reflects that. 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 |
What moves the price most:
- Scaffolding and access to the rear
- Bathrooms or en-suites on the first floor
- Steel beams where walls are opened up
- Roof design and how it joins the existing roof
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a double-storey extension in Kingswood?
Here is how the rules work for a double-storey extension 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most double-storey extensions:
- Brick or block walls, floors and a roof tied into the house
- Opening up at both levels with steel beams
- Electrics, heating, plumbing and plastering
- Foundations, drainage and scaffolding
- Building control sign-off
- Design drawings and planning application
How long does it take?
Expect 14 to 20 weeks on site, after planning and building control approval. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Kingswood
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
Projects in Kingswood (BS15) are surveyed in person before we quote, so the price reflects your actual property.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 Kingswood
How much does a double-storey extension cost in Kingswood?
In Kingswood, 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.
Can I live at home during the work?
Most families stay put. The shell is built first and the house is opened up late in the job, so disruption inside is limited to a few weeks.
Do you build double-storey extensions in Kingswood?
Yes. We build double-storey extensions across Kingswood, including postcodes BS15. Every project starts with a free home visit.
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.