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 Bracknell?
In Bracknell, a double-storey extension typically costs £1,850–£2,800 per m² of floor area (both floors), including VAT at 20% (standard rate). For a typical 36 m² project that is roughly £66,500–£101,000. Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for Bracknell. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (25 m²) | £46,000–£70,000 |
| Typical project (36 m²) | £66,500–£101,000 |
| Larger project (50 m²) | £92,500–£140,000 |
| Rate per m² | £1,850–£2,800 |
What moves the price most:
- Steel beams where walls are opened up
- Brick matching and external finishes
- Roof design and how it joins the existing roof
- Scaffolding and access to the rear
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 Bracknell?
Whether you need planning permission depends on your house and its location 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
The work we manage on a double-storey extension:
- Design drawings and planning application
- Structural engineer’s calculations
- Electrics, heating, plumbing and plastering
- Opening up at both levels with steel beams
- Windows, doors and staircase alterations
- Foundations, drainage and scaffolding
How long does it take?
Expect 14 to 20 weeks on site, after planning and building control approval. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Bracknell
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
Projects in Bracknell (RG12 and RG42) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 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 Bracknell
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.
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 close can it be to my neighbour?
Councils look at loss of light and outlook for neighbours. Many apply a 45-degree guideline from the nearest neighbouring window. We design to the council’s published guidance to give the application the best chance.
How long does a double-storey extension take in Bracknell?
Typically 14 to 20 weeks on site, after planning and building control approval. Design and approvals beforehand usually take 3 to 4 months.
How much does a double-storey extension cost in Bracknell?
In Bracknell, a double-storey extension typically costs £1,850–£2,800 per m² of floor area (both floors), including VAT at 20% (standard rate). A typical 36 m² project comes to roughly £66,500–£101,000. Your fixed price depends on the survey and drawings.