Planning permission for extensions in Bedfordshire, explained

Permitted development rights let you build certain extensions without a full planning application, provided you stay within set limits on size, height and position. A single-storey rear extension on a semi-detached or terraced house can generally go up to 6 metres from the original rear wall (8 metres for a detached house), subject to height limits and, in some cases, a neighbour consultation process rather than a full application.

These rules get tighter for side extensions, upper floors, and anything near a boundary, and they don't apply at all in some conservation areas or to listed buildings. This is exactly why we check your specific property before designing anything, rather than assuming a rule of thumb applies.

Double-storey extensions, wraparound extensions, and anything exceeding permitted development limits need a full application to the local planning authority. This adds time, typically 8 weeks for a decision once the application is validated, sometimes longer if it's called in for committee review, and adds the cost of drawings and the application fee.

Even if a project falls under permitted development, you can apply for a Lawful Development Certificate, a formal confirmation from the council that the work doesn't need planning permission. It costs less than a full application and isn't compulsory, but it's useful to have on file if you ever sell the house and a buyer's solicitor asks for proof.