East Cowes, Isle of Wight
Semi-detached rear extension in East Cowes
Thinking about a semi-detached rear extension in East Cowes? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
East Cowes is covered from our Isle of Wight round, including PO31 and PO32. In East Cowes we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
Ask about a site visit
Visits here are by arrangement; we'll confirm before booking.
East Cowes is outside our regular coverage, so visits and projects here are by arrangement: we confirm whether we can take the job, and agree any travel costs, before the first visit.
How much does a semi-detached rear extension cost in East Cowes?
In East Cowes, our guide for a semi-detached rear extension is £2,130–£3,470 per square metre including VAT for a standard specification. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £25,500–£41,500 |
| 4 m wide × 5 m deep (20 m²) | £42,500–£69,500 |
| 4 m wide × 6 m deep (24 m²) | £51,000–£83,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in East Cowes?
Here is how the rules in England apply to a semi-detached rear extension in East Cowes.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in East Cowes like to extend?
Commuter semis and detached houses make up much of East Cowes, and longer gardens make England's prior approval route for deeper rear extensions worth considering.
How a semi-detached rear extension in East Cowes comes together
Look round and measure
We see the back of the house, measure it, check the drains and boundaries and hear what you need.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Semi-detached rear extensions near East Cowes
Neighbouring places we cover include Cowes (0.5 miles) and Newport (3.9 miles).
- Semi-detached rear extension in Cowes
- Semi-detached rear extension in Newport
- Semi-detached rear extension in Ryde
- Semi-detached rear extension in Sandown
- Semi-detached rear extension in Shanklin
Other work in East Cowes:
FAQ
Semi-detached rear extension questions in East Cowes
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
How much does a semi-detached rear extension cost in East Cowes?
As a guide, £2,130–£3,470 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £25,500–£41,500 at that rate. Your written price follows the survey.
Do I need a party wall agreement?
Usually with the attached neighbour, in England and Wales.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Do I need planning permission for a rear extension in East Cowes?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
What postcode areas do you cover around East Cowes?
Including PO31 and PO32, and the surrounding Isle of Wight area.