Does a conservation area mean I cannot extend?

No. It means tighter permitted development allowances and greater attention to design and materials. Many extensions in conservation areas are approved, usually through a planning application rather than permitted development.

Do building regulations still apply if I do not need planning permission?

Yes. Planning permission and building regulations are separate. Most extensions need building regulations approval regardless of the planning route.

What if a previous owner already extended?

Earlier extensions usually count towards the permitted development allowance. Check what has been built before assuming a further extension is allowed.

Do I need planning permission for an extension?

Some extensions need a planning application and some are allowed under permitted development, subject to limits and conditions. Which applies depends on your property, not on the type of extension alone.

The short answer

Many single-storey rear extensions on houses fall within permitted development if they stay inside the size, height and position limits set out in national legislation. Larger or two-storey work, work to the front, and work on flats or maisonettes usually needs a planning application.

Permitted development is not a blanket right. It applies to houses, not flats, and it can be removed or restricted for an individual property.

What commonly removes permitted development rights

A conservation area, National Park, Area of Outstanding Natural Beauty or other designated land, where the allowances are tighter.
A listed building, where listed building consent may be needed for work that would otherwise be unremarkable.
An Article 4 direction, which the local authority uses to withdraw specific permitted development rights in a defined area.
A planning condition on the original permission, common on newer estates, removing rights for extensions or outbuildings.
Previous extensions, which count towards the allowance even if you did not build them.

How to check your own property

Start with the facts about the property: its type, whether it is listed, whether it sits in a conservation area or on designated land, and what has already been built. Then look at what you want to do and measure it against the relevant limits.

Where the position is not clear-cut, a lawful development certificate gives you a formal confirmation from the local authority that the work is permitted development. It is an application in its own right, with a fee, but it is useful evidence when you later sell the property.

Why an online answer is never the final word

Published records are incomplete and they lag behind reality. An absence of a record is not confirmation that a restriction does not exist, and a record that exists may not apply in the way it first appears.

Our free planning check screens the information available for your property and flags what needs a closer look. It does not confirm what you can build; that needs professional review of the property and the proposal.

Questions homeowners ask

Does a conservation area mean I cannot extend?: No. It means tighter permitted development allowances and greater attention to design and materials. Many extensions in conservation areas are approved, usually through a planning application rather than permitted development.
Do building regulations still apply if I do not need planning permission?: Yes. Planning permission and building regulations are separate. Most extensions need building regulations approval regardless of the planning route.
What if a previous owner already extended?: Earlier extensions usually count towards the permitted development allowance. Check what has been built before assuming a further extension is allowed.

Official sources

Check your own property

Tell us about your home and plans, and we will review what needs a closer look.

Request my free planning check