Rochester, Kent
Semi-detached rear extension in Rochester
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Rochester 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.
We cover Rochester (ME1, ME4 and ME5) as part of our Kent work. Semi-detached houses are common across Kent, and their side access makes rear extensions quicker to build.
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 Rochester?
A semi-detached rear extension in Rochester is priced at £2,130–£3,470 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a semi-detached rear extension in Rochester?
The planning route for a semi-detached rear extension in Rochester is set by England's householder rules and your council.
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 Rochester like to extend?
Around Rochester the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.
How a semi-detached rear extension in Rochester 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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 Rochester
From Rochester, the nearest places we also cover are Chatham (1.1 miles) and Strood (1.3 miles).
- Semi-detached rear extension in Chatham
- Semi-detached rear extension in Strood
- Semi-detached rear extension in Gillingham
- Semi-detached rear extension in Snodland
- Semi-detached rear extension in Gravesend
Other work in Rochester:
FAQ
Semi-detached rear extension questions in Rochester
Can you match the brick or stone on my Rochester house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
How much does a semi-detached rear extension cost in Rochester?
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.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
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.
Is the site visit in Rochester free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do you handle building control in Rochester?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.