Do I Need Planning Permission for a Home Extension in Devon?

Homeowners across Devon often ask the same question when planning to extend their home – do I need planning permission, or can I build under permitted development?

The short answer is: it depends on the size, location, and design of the extension, as well as whether your property has any restrictions attached to it.

When planning permission is usually required

You’ll normally need planning permission if:

• The extension is two storeys

• It extends beyond permitted development size limits

• The property is listed or in a conservation area

• The design significantly alters the appearance of the home

• Previous permitted development rights have been removed

Local planning authorities in Devon are particularly sensitive to scale, neighbouring impact, and materials – especially in rural and coastal locations.

What counts as permitted development?

Many single-storey rear and side extensions fall under permitted development, meaning no full planning application is required, provided:

• The extension stays within height and depth limits

• Materials are similar in appearance to the existing property

• The extension does not reduce privacy or daylight to neighbours

However, permitted development is not automatic. Subtle details can push a project outside the rules.

Why professional advice matters

One of the most common mistakes homeowners make is assuming they don’t need approval – only to find issues later when selling or insuring the property.

An architect can:

• Confirm whether planning permission is required

• Design an extension that complies with regulations

• Liaise with the local planning authority

• Reduce the risk of delays or refusals

Our advice

If you’re considering a home extension in Devon, get clarity early. A short professional review can save months of frustration and unexpected redesign costs.