Double-storey extensions across Canvey Island
We design and build double-storey extensions for houses in Canvey Island, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in Canvey IslandFrom £40,000 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsSS7, SS8
Working in Canvey Island
Postcode districts we cover around Canvey Island include SS7, SS8. The same team covers Benfleet (2 miles), Hadleigh (2 miles), Rayleigh (5 miles), Southend-on-Sea (6 miles), all within easy reach.
Just over the Kent border, Gillingham is about 9 miles away. Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
Double-storey extension prices in Canvey Island
Labour and material costs vary across the UK, so for Canvey Island we use our East of England factor (×1.06). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Canvey Island: £1,640 to £3,180 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £40,000 – £48,500 | £45,500 – £60,000 | £58,500 – £76,500 |
| 4 m × 4 m, two floors 32 m² | £52,500 – £63,000 | £61,000 – £80,000 | £78,000 – £102,000 |
| 4 m × 6 m, two floors 48 m² | £78,500 – £94,500 | £91,500 – £120,000 | £117,000 – £153,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
When a double-storey extension makes sense
- Growing families who need a bedroom as well as a bigger kitchen
- Houses with enough distance to the rear or side boundary
- Homeowners who would otherwise consider moving
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Planning and approvals in Canvey Island
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
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
We visit your Canvey Island home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about a double-storey extension in Canvey Island
Do you cover all of Canvey Island?
Yes. We cover Canvey Island and the surrounding parts of Essex. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Canvey Island, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do I need building regulations approval in Canvey Island?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do I need a Party Wall Agreement?
If you are in England or Wales and the work involves a shared wall or digging foundations close to a neighbour, the Party Wall etc. Act 1996 applies and notices must be served before work starts. We tell you which notices are needed.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,640 to £3,180 per m² of new floor area including VAT, compared with £1,860 to £3,600 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Canvey Island
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.