Permitted Development: What You Can Build Without Planning Permission

What permitted development is

The rules are in the General Permitted Development Order, which grants planning permission for set kinds of work, so long as the work stays inside every limit and condition that applies to it. The government's technical guidance puts the idea simply: it lets you improve and extend your home without a planning application where one would be out of proportion to the impact of the work.

Part 1 of the Order covers a house and its garden, split into classes by type of work. A project has to meet the rules of every class it touches. The guidance gives the example of a two-storey rear extension whose roof joins the main roof: it has to pass the extension rules (Class A) and the roof rules (Class C), and the dormer rules (Class B) too if it adds a dormer.

Who doesn't have the rights, or has fewer

• Flats and maisonettes: the Order's definition of a house leaves out any building containing flats, so householder permitted development doesn't apply. The Planning Portal says the same.
• Homes created by a change of use: a house made from a shop, farm building or similar under the change of use rights can't use them either. The Planning Portal says planning permission is usually needed for an extension.
• Protected areas (conservation areas, National Parks, areas of outstanding natural beauty, the Broads and World Heritage Sites): the rights are cut back. There are no side extensions, no rear extensions of more than one storey, no larger rear extensions by prior approval, no dormers, no extra storeys and no cladding the outside in stone, render, pebble dash, timber, plastic or tiles.
• Listed buildings: garden buildings aren't permitted anywhere in a listed building's grounds, and the Planning Portal says listed buildings have different requirements. Talk to your council first.
• Article 4 directions and planning conditions: a council can remove rights across an area with an article 4 direction (the Planning Portal says they're most common in conservation areas), and the original planning permission for your house may have removed them with a condition. Either way, the work they cover needs a planning application.

We'd check all of this with the council before paying for drawings, and on a house built in the last few decades we'd ask whether its original planning permission removed any rights.

What it covers, project by project

The main limits, from Part 1 of the Order. Each class has more conditions than these, so check the full rules for your project.

• Rear extensions (Class A): single storey, up to 3m beyond the original back wall (4m if detached) and no more than 4m high. Two storeys: up to 3m deep and at least 7m from the boundary opposite the back wall. Within 2m of a boundary, the eaves can't be over 3m. See house extension costs, which has a checker for these limits.
• Side extensions (Class A): single storey, up to 4m high and no wider than half the original house.
• All extensions: nothing beyond the front wall (or a side wall facing a road), nothing higher than the existing roof or eaves, materials similar in appearance to the house, and no balconies, verandas or raised platforms over 0.3m. Upper-floor side windows must be obscure glazed and non-opening below 1.7m.
• Loft dormers (Class B): up to 40m³ of extra roof space on a terrace, 50m³ on other houses; not on a roof slope that faces a road at the front; no higher than the existing roof; set back at least 0.2m from the eaves where practicable. See loft conversion costs.
• Rooflights and other roof alterations (Class C): can stand no more than 0.15m proud of the roof slope and no higher than the roof. See Velux window costs.
• Porches (Class D): no more than 3m² of ground area, no higher than 3m, and not within 2m of a boundary with a road. See porch costs.
• Garden buildings (Class E): single storey, not in front of the house, no higher than 4m with a dual-pitched roof or 3m otherwise, 2.5m within 2m of a boundary, with eaves no higher than 2.5m. It must be for use incidental to the house, so not a separate home. See garden room costs.
• Driveways and paths (Class F): in front of the house, a new or replaced hard surface over 5m² must be porous or drain to a permeable area within the garden. See driveway costs.
• Chimneys and flues (Class G): less than 1m above the highest part of the roof. See log burner costs.
• Satellite dishes (Class H): no more than 2 on the house and garden together, with limits on size and position. See satellite dish costs.

Extensions and garden buildings together can't cover more than 50% of the land around the original house. Other parts of the Order cover fences, gates and walls (Part 2) and solar panels and other small-scale renewables (Part 14).

"Original house" and earlier extensions

Most of the limits are measured from the original house: as it stood on 1 July 1948 if it's older than that, or as first built if it's newer. So an extension a previous owner built counts against your allowance. If a new extension joins on to an old one, the rules look at the two together, and the loft limit is extra space over the original roof.

Heights are measured from the ground next to the building, and on a slope from the highest point of the ground beside it. Decking doesn't count as ground level.

Prior approval: bigger extensions and extra storeys

Two kinds of work are permitted development only after you've applied to the council for prior approval.

• Larger single-storey rear extensions: up to 6m (8m detached), not in protected areas. The council tells your neighbours, who have at least 21 days to comment. If one objects, the council looks at the effect on their home. You can start when the council says approval isn't needed, grants it, or hasn't decided within 42 days.
• Extra storeys (Class AA): up to 2 more storeys on a house of two or more (1 on a bungalow), for a house built between 1 July 1948 and 28 October 2018, not in a protected area and not already extended upwards. The roof can't go over 18m, or more than 7m above the existing roof (3.5m on a bungalow). On a semi or terrace it can't end up more than 3.5m above the neighbours' roofs. The council considers the effect on neighbours and how the house looks, and the work has to be finished within 3 years.

There's a fee for both: our house extension cost guide lists the main planning fees.

What it doesn't cover, and how to prove it

Permitted development is planning permission and nothing else. The government's guidance is clear that it doesn't remove the need for building regulations approval or for a party wall notice where the Party Wall Act applies.

Lawful development certificate. You don't have to have one, but it's the way to be certain. You apply to the council with enough information for it to decide, and pay a fee. The Planning Portal says you can appeal if it isn't decided within eight weeks. We'd get one for any extension or loft near the limits, so you have proof when you sell.

If you get it wrong: work outside the rules needs planning permission, and for work finished on or after 25 April 2024, councils have 10 years to take enforcement action against it.

Have the rules changed?

When we checked on 20 October 2026, the Order on legislation.gov.uk was up to date with every change in force by 18 October 2026. The government ran a consultation in February 2024 on giving householders more flexibility, but hadn't published its response, so none of those proposals are law. We check the rules each month and update this guide when they change.

Frequently asked questions