Most single storey extensions in Devon can be built without planning permission thanks to permitted development rights, but the rules tighten considerably if you live in a conservation area or the East Devon National Landscape. Here is how to work out where your project stands before you spend money on drawings.
Permitted development rights let you extend your home without a planning application, provided the extension stays within set limits. For a detached house, a single storey rear extension can normally project up to 4 metres from the original rear wall; for a semi detached or terraced house the limit is 3 metres. Under the larger home extensions scheme these limits rise to 8 metres and 6 metres respectively, but you must notify the council first through the prior approval process so neighbours can comment.
There are other conditions that catch people out. The extension must not cover more than half the land around the original house, must not be taller than 4 metres, and the materials should be similar in appearance to the existing property. Side extensions are limited to single storey, a maximum of 4 metres high, and no more than half the width of the original house. The word original matters: it means the house as first built or as it stood in 1948, so if a previous owner already extended, some or all of your allowance may be used up.
Budleigh Salterton, Sidmouth, Exmouth's coastal fringe and much of the surrounding countryside sit within the East Devon National Landscape, formerly known as the Area of Outstanding Natural Beauty. On this designated land, permitted development rights are reduced: the larger home extensions scheme does not apply, side extensions need planning permission, and cladding the outside of your house also requires an application.
Conservation areas add another layer. Budleigh Salterton, Otterton, East Budleigh and several other local villages have conservation areas covering their historic centres, where rear extensions of more than one storey need permission and demolition may need consent too. If your home is listed, you will need listed building consent for almost any alteration, inside or out, regardless of size.
Some projects need permission wherever you live in Devon. Any two storey extension that comes within 7 metres of your rear boundary, anything forward of the principal elevation facing a road, raised platforms or verandas over 300mm high, and extensions on flats or maisonettes all require an application, because permitted development only applies to houses.
A householder planning application to East Devon District Council currently costs 258 pounds, and the council aims to decide within 8 weeks. Budget for drawings from an architect or architectural technician as well, typically 1,000 to 3,000 pounds depending on the complexity of the scheme. If your project sits near the permitted development limits, a lawful development certificate (129 pounds) is worth having: it is formal confirmation that your extension is lawful, which solicitors increasingly ask for when you sell.
Even when no planning permission is needed, virtually every extension must comply with building regulations, which cover structure, insulation, drainage, fire safety and electrics. You can use Devon Building Control Partnership or an approved private inspector, and the work will be inspected at key stages from foundations through to completion.
In practice, the sensible order is: check whether your address is in a conservation area or the National Landscape using East Devon District Council's online mapping, confirm what previous extensions exist, then decide whether you need a planning application, prior approval or just building regulations sign off. A builder who works locally will usually spot the constraints early, and it is far cheaper to find out before the footings go in than after an enforcement letter arrives.
East Devon District Council targets a decision within 8 weeks of validating a householder application, though extensions to that timescale are fairly common if the case officer requests amendments. Prior approval for a larger single storey extension takes up to 42 days.
A porch is usually permitted if it is under 3 square metres in floor area, less than 3 metres high and at least 2 metres from a boundary with a highway. Conservatories follow the same rules as any other single storey extension, so most modest ones do not need permission outside designated areas.
The council can serve an enforcement notice requiring alteration or removal, and an unauthorised extension causes real problems when you sell. You can apply for retrospective permission, but there is no guarantee it will be granted, so it is always safer to check first.
Tell us about your project. Paul personally reviews every enquiry and replies within the working day.