Penrith, Cumbria
Semi-detached rear extension in Penrith
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Penrith 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.
Penrith is covered from our Cumbria round, including CA11. Semi-detached houses are common across Cumbria, 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 Penrith?
For Penrith we work from the North West England rate: £1,790–£2,910 per square metre of new floor, including VAT, standard specification. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,500–£35,000 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£58,500 |
| 4 m wide × 6 m deep (24 m²) | £43,000–£70,000 |
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 Penrith?
Here is how the rules in England apply to a semi-detached rear extension in Penrith.
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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Penrith like to extend?
Penrith has long runs of terraced houses with back yards and alleys, plus 1930s semis further out. Yard extensions on terraces are often single-storey and close to both boundaries.
How a semi-detached rear extension in Penrith 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
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 Penrith
Close by, we work in Carlisle, about 17.4 miles away, and Kendal, about 23.4 miles away.
- Semi-detached rear extension in Carlisle
- Semi-detached rear extension in Kendal
- Semi-detached rear extension in Annan
- Semi-detached rear extension in Workington
- Semi-detached rear extension in Hexham
Other work in Penrith:
FAQ
Semi-detached rear extension questions in Penrith
What postcode areas do you cover around Penrith?
Including CA11, and the surrounding Cumbria area.
Can you match the brick or stone on my Penrith house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
Do you handle building control in Penrith?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Is the site visit in Penrith free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do I need planning permission for a rear extension in Penrith?
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.