Eastleigh, Hampshire
Semi-detached rear extension in Eastleigh
For homes in Eastleigh, a semi-detached rear extension is often the simplest way to gain space without moving. Single or two-storey extensions for semi-detached houses, with side access and one party wall. We take it from survey to completion certificate.
We cover Eastleigh (SO50 and SO53) as part of our Hampshire work. In Eastleigh we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a semi-detached rear extension cost in Eastleigh?
Guide prices for a semi-detached rear extension in Eastleigh start from our South East England rate of £2,130–£3,470 per square metre, including VAT. 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 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a semi-detached rear extension in Eastleigh?
Whether your semi-detached rear extension in Eastleigh needs a planning application depends on its size, your house and any local restrictions.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is 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 Eastleigh like to extend?
Commuter semis and detached houses make up much of Eastleigh, and longer gardens make England's prior approval route for deeper rear extensions worth considering.
How a semi-detached rear extension in Eastleigh comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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 Eastleigh
From Eastleigh, the nearest places we also cover are Bishopstoke (0.9 miles) and Fair Oak (2.3 miles).
- Semi-detached rear extension in Bishopstoke
- Semi-detached rear extension in Fair Oak
- Semi-detached rear extension in Portswood
- Semi-detached rear extension in Hedge End
- Semi-detached rear extension in Southampton
Other work in Eastleigh:
FAQ
Semi-detached rear extension questions in Eastleigh
How much does a semi-detached rear extension cost in Eastleigh?
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.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
What postcode areas do you cover around Eastleigh?
Including SO50 and SO53, and the surrounding Hampshire area.
Is the site visit in Eastleigh free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do you handle building control in Eastleigh?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.