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England

Rear extensions in Cumbria

Across Cumbria we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Carlisle, Barrow in Furness and Kendal.

Rear extension on a house typical of the area

What are homes in Cumbria like to extend?

Cumbria 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.

Rear extension prices in Cumbria

North West prices sit below our West Midlands baseline; access on terraced streets is the main variable. Per square metre including VAT, standard specification:

ExtensionPer m²
Single-storey rear extension£1,790–£2,910
Two-storey (per m² across both floors)£1,690–£2,540
Side return£2,160–£3,570
Wraparound£2,070–£3,380
Glass-led£2,630–£4,510

Planning and building rules in Cumbria

Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.

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.

Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.

Because rear extensions often sit on or near the boundary, the Party Wall etc. Act 1996 usually applies in England. Notices go out one or two months before work depending on the type of work, and a surveyor's award is only needed if a neighbour does not consent.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.

Rear extensions we build in Cumbria

Towns and districts in Cumbria

The main places we cover in Cumbria include Carlisle, Barrow in Furness and Kendal, across postcode areas CA and LA.

Main towns in Cumbria
TownPostcode districtsNearest town we also cover
CarlisleCA1, CA2, CA3Annan (14.2 miles)
Barrow in FurnessLA13, LA14, LA15Ulverston (7.9 miles)
KendalLA8, LA9Ulverston (16.7 miles)
WhitehavenCA28Workington (6.7 miles)
WorkingtonCA14Whitehaven (6.7 miles)
PenrithCA11Carlisle (17.4 miles)
UlverstonLA12Barrow in Furness (7.9 miles)

Areas near Cumbria

FAQ

Questions people ask

How much does a rear extension cost in Cumbria?

As a guide, £1,790–£2,910 per square metre including VAT for a standard single-storey extension at North West England rates.

Do I need planning permission in Cumbria?

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.

Which towns in Cumbria do you cover?

7 towns and districts, including Carlisle, Barrow in Furness and Kendal.

Do you handle building control?

Yes. We apply to the council or a registered building control approver and hand over the completion certificate.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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