Double-storey extensions across Fleet
A double-storey extension in Fleet starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in FleetFrom £42,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsGU13, GU51, GU52

How much does a double-storey extension cost in Fleet?
These guide figures apply our South East England adjustment (×1.12) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Fleet: £1,740 to £3,360 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £42,500 – £51,000 | £48,000 – £63,500 | £61,500 – £81,000 |
| 4 m × 4 m, two floors 32 m² | £55,500 – £66,500 | £64,500 – £84,500 | £82,000 – £108,000 |
| 4 m × 6 m, two floors 48 m² | £83,000 – £99,500 | £96,500 – £126,500 | £123,500 – £161,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Extensions in and around Fleet
Site visits are available across Fleet (GU13, GU51, GU52). The same team covers Farnborough (3 miles), Aldershot (4 miles), Yateley (4 miles), Basingstoke (11 miles), all within easy reach.
Just over the Berkshire border, Sandhurst is about 5 miles away. Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Will the council need to approve it?
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
What we take care of
- Measured survey, design and planning drawings
- Insulation, plastering, electrics and plumbing to finish
- Foundations sized for two floors
- Householder planning application where needed
- Breaking through at both levels, stairs and landing changes where needed
- Ground and first floor structure, roof tied into the existing roof
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Double-storey extension questions answered
Will my neighbours in Fleet be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do you cover all of Fleet?
Yes. We cover Fleet and the surrounding parts of Hampshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Fleet?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Does a double-storey extension need planning permission?
Often, yes. In England a two-storey rear extension can be permitted development only if it projects no more than 3 m and sits at least 7 m from the rear boundary, with matching roof pitch and obscure side windows. Side extensions over one storey always need planning permission. We confirm the route at the survey.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,740 to £3,360 per m² of new floor area including VAT, compared with £1,960 to £3,810 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Fleet
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.