Reading, Berkshire
Semi-detached rear extension in Reading
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Reading and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Reading sits in Berkshire, with postcode districts including RG1, RG2, RG4 and RG30. In Reading 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 Reading?
In Reading, 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a semi-detached rear extension in Reading?
Planning for a semi-detached rear extension in Reading follows the English householder rules.
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.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
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 Reading like to extend?
Commuter semis and detached houses make up much of Reading, and longer gardens make England's prior approval route for deeper rear extensions worth considering.
How a semi-detached rear extension in Reading comes together
Look round and measure
A free visit to 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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Semi-detached rear extensions near Reading
We also build rear extensions for semi-detached houses in nearby Lower Earley (3.0 miles) and Henley-on-Thames (6.1 miles).
- Semi-detached rear extension in Lower Earley
- Semi-detached rear extension in Henley-on-Thames
- Semi-detached rear extension in Wokingham
- Semi-detached rear extension in Crowthorne
- Semi-detached rear extension in Yateley
Other work in Reading:
FAQ
Semi-detached rear extension questions in Reading
Can you match the brick or stone on my Reading house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do I need planning permission for a rear extension in Reading?
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.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
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.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.