Planning permission for home improvements in the UK

Updated 26 October 2026 · SK Home Improvements

What is planning permission and when do you need it?

Planning permission is formal consent from your local planning authority, usually the council, to carry out building work or change how a property is used. Home improvements that need it typically include larger extensions, major roof changes, and work that changes the look of a house in a sensitive area. Internal work such as a new kitchen, bathroom or replastering does not need planning permission unless the building is listed.

Planning is about how a building looks, how it affects neighbours and the area, and how land is used. It is separate from Building Regulations, which cover how the work is built. Most projects need to think about both, and our Building Regulations guide covers the second part.

What is permitted development?

Permitted development rights allow certain types of work to a house without a planning application, as long as the work stays within set limits and conditions. Each UK nation has its own rules, but they follow similar ideas: limits on size, height and closeness to boundaries, restrictions on work facing a road, and materials that match the existing house.

Some points apply widely:

• Permitted development rights for houses generally do not apply to flats and maisonettes.
• Rights can be removed by a planning condition, which is common on newer estates.
• Limits are measured against the original house, so earlier extensions use up some of the allowance.
• Rights are reduced for listed buildings and in conservation areas and other protected areas.

If you are not sure whether your project qualifies, you can apply to the council for a certificate confirming it is lawful. The name of that certificate differs by nation, as explained below.

How does planning work in England?

In England, planning applications go to your local council, and householder permitted development is set out in national rules. At the time of writing, examples for houses in England include:

• A single-storey rear extension up to 3 m deep on a semi-detached or terraced house, or 4 m on a detached house, and no more than 4 m high. Through the prior approval process, these can rise to 6 m and 8 m.
• A loft conversion adding up to 40 cubic metres on a terraced house or 50 cubic metres on a semi-detached or detached house, not extending beyond the roof slope facing a road.
• A porch with a ground floor area up to 3 square metres, no higher than 3 m, and not within 2 m of a boundary with a road.
• A front-garden hard surface over 5 square metres only if it is permeable or drains to a permeable area within the property.

The original house means the house as it was first built, or as it stood on 1 July 1948 if it is older. To confirm that a project is permitted development, you can apply for a Lawful Development Certificate. Article 4 directions can remove specific rights in particular streets or areas.

How does planning work in Wales?

Wales has its own planning law and its own permitted development rules, set by the Welsh Government. They are similar in outline to England's, covering rear extensions, roof alterations, porches and outbuildings, but the details differ, and there is no direct equivalent of England's prior approval scheme for larger rear extensions. Applications go to your local planning authority, which is the county or county borough council or, in a national park, the national park authority.

To confirm that work is lawful without a full application, you can apply for a Certificate of Lawfulness of Proposed Use or Development, usually called a Certificate of Lawfulness. Article 4 directions are used in Wales to remove specific rights, often in conservation areas. Listed buildings in Wales are designated by the Welsh Government through Cadw, and listed building consent comes from the local planning authority.

How does planning work in Scotland?

Scotland has a separate planning system, run by local councils and, in some areas, national park authorities, under Scottish law, with its own householder permitted development rules. These cover things like single-storey extensions, dormers, porches and hard surfaces, with conditions on size, height and distance from boundaries, and they have been updated in recent years. Rights are more restricted in conservation areas, and listed buildings need listed building consent.

To confirm in advance that a project does not need permission, you can apply for a Certificate of Lawfulness of Proposed Use or Development. Separately, most building work in Scotland, including extensions, loft conversions and structural alterations, needs a building warrant from the council's building standards service before work starts, and a completion certificate once it is finished. Planning permission and a building warrant are two different consents, and you may need both.

How does planning work in Northern Ireland?

In Northern Ireland, the 11 district councils handle most planning applications, under Northern Ireland's own planning law and permitted development rules for householders. These set limits for extensions, roof alterations, porches and outbuildings that differ in detail from the rest of the UK. Conservation areas and areas of townscape character restrict what can be done without permission, and listed buildings need listed building consent.

To confirm a project is lawful before you start, you can apply to the council for a Certificate of Lawfulness of Proposed Use or Development. Building control is also run by the councils, under the Building Regulations (Northern Ireland), so approval for the building work is a separate step from planning.

Do listed buildings, conservation areas and Article 4 directions change the rules?

Yes. Across the UK, protected buildings and areas have stricter rules, and work that would normally be permitted development can need an application.

• Listed buildings: listed building consent is needed for any work, inside or out, that affects the building's character, including replacing windows, removing walls or changing fireplaces. Carrying out such work without consent is a criminal offence.
• Conservation areas: permitted development is reduced, so side extensions, some roof changes and changes to cladding or render often need permission. Some tree work also needs notice to the council.
• Article 4 directions (England and Wales): these remove specific permitted development rights in a defined area, such as replacing windows or doors or altering front boundary walls.

Title deeds and leases can also restrict work, separately from planning, so check yours as well.

What happens if you build without the right permission?

If work that needed planning permission goes ahead without it, the council can ask for a retrospective application and, if that is refused, take enforcement action requiring the work to be changed or removed. Councils can act for several years after work is finished, and the time limits differ between nations.

Missing permissions also tend to surface when you sell, because the buyer's solicitor will ask for planning decisions, certificates and building control completion certificates. A certificate of lawfulness obtained before work starts gives clear evidence that the work did not need permission.

How do we handle planning on your project?

We check the planning position for your property before we quote, including whether it is listed, in a conservation area, or covered by an Article 4 direction or a planning condition. Where an application or certificate is needed, we can arrange the drawings and the application as part of the job, and we build the decision time into the programme.

Rules change, and each council applies them to its own area, so treat the figures in this guide as a starting point and confirm with your council. For a guide price, use our guide-price tool, or see how we approach single-storey extensions and loft conversions.

Related services

• Single-storey extensions: guide £35,000–£75,000 inc VAT
• Loft conversions: guide £30,000–£65,000 inc VAT
• Porches: guide £3,500–£8,000 inc VAT

Figures in this guide are typical UK ranges including VAT where it applies. They are not quotes. Rules on planning and building control differ between England, Wales, Scotland and Northern Ireland and change over time, so we check what applies to your property before quoting.