Permitted development rights explained
Permitted development is the legal shortcut that lets UK homeowners build, extend, and alter their homes without applying for planning permission. It’s set out in a single piece of secondary legislation — the General Permitted Development Order 2015, usually called the GPDO — and it covers a lot more than most people realise. This guide walks through what permitted development actually is, the classes that matter for homeowners, and the things that can remove your rights.
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Check my property — freeWhat permitted development rights actually are
When Parliament passes planning law, the default rule is that any development — from a rear extension to a new roof — needs planning permission. Permitted development is the exception to that default. The government maintains a list of specific types of work that are so common, so low-impact, or so clearly defined that requiring an application every time would be a waste of everyone’s time. If your work meets the conditions on that list, you don’t need to apply. You just build it.
The list is maintained in the GPDO 2015. It’s organised into “Parts” (numbered 1 to 19), with each Part covering a different type of development — Part 1 for houses, Part 2 for minor works like fences and gates, Part 14 for renewable energy, and so on. Within each Part, individual rights are grouped into “Classes” (A, B, C, D, E…). Each Class has its own dimension limits, materials rules, and conditions.
Meet every condition in a Class and the work is lawful — permitted development. Miss one condition and the work falls outside the Class, which means it either needs a full planning application or it’s not allowed at all.
The permitted development classes that matter for homeowners
Most of what homeowners care about sits in Schedule 2, Part 1 of the GPDO — the Part that covers development within the curtilage of a dwellinghouse. Here are the Classes in that Part, with the headline rules for each.
Class A — House enlargements, improvements and alterations
The big one. Covers rear, side, and two-storey extensions, and any other enlargement of a dwellinghouse. The headline limits: 3m single-storey rear depth on terraced and semi-detached houses (4m on detached), 4m overall height, 3m eaves, and the whole extension must be built with matching materials. Two-storey rear extensions are permitted up to 3m deep provided they stay 7m from the rear boundary. Side extensions can’t exceed half the width of the original house and can’t be built at all on designated land.
See the rear extension guide and the side extension guide.
Class B — Enlargements of the roof (loft conversions)
Allows additions to the roof space (typically dormers) up to 40 m³ on terraced houses, or 50 m³ on semi-detached and detached houses. Dormers are permitted on rear and side slopes but not on the principal elevation facing a highway. The ridge line can’t be raised. Class B doesn’t apply at all in conservation areas or on designated land.
See the loft conversion guide.
Class C — Other alterations to the roof
Re-roofing, rooflights (Velux-type windows), and similar changes. Rooflights mustn’t protrude more than 0.15m from the roof plane. Materials must be similar in appearance to the existing roof. Listed buildings are excluded.
Class D — Porches
A porch up to 3 m² in floor area, 3m in height, and at least 2m from any highway. Exceeding any of those limits — even by a small amount — kicks the project out of Class D and you’ll need planning permission. See the porch guide.
Class E — Outbuildings
Detached buildings within the curtilage — sheds, home offices, summer houses, garden rooms, pools. They must sit behind the front elevation of the house, not exceed 2.5m in height if within 2m of a boundary (4m otherwise, with a 3m eaves cap), and must be for purposes “incidental to the enjoyment of the dwellinghouse.” Total coverage of extensions and outbuildings combined can’t exceed 50% of the curtilage. A building used as independent living accommodation loses all Class E protection. See the outbuilding guide.
Class F, G, H — Hard standing, chimneys, satellite dishes
Smaller classes covering driveways and hard standing (must use porous materials for areas over 5 m²), chimney flues and vents, and antennas/satellite dishes. Each has its own set of conditions.
Other Parts of the GPDO homeowners often use
Part 1 is the main one, but a few other Parts apply to things homeowners do around the house.
- Part 2 — Minor operations. Fences, walls, and gates. Class A allows boundary treatments up to 2m in height (1m if adjacent to a highway), as permitted development. Listed buildings need consent. See the fences and walls guide.
- Part 14 — Renewable energy. Solar panels on the roof of a house, air source heat pumps, and small wind turbines. Most installations are permitted development subject to specific technical limits (e.g. panels can’t project more than 0.2m from the roof slope).
- Part 16 — Electronic communications. Covers broadband and telecoms infrastructure, including some small external equipment.
Six things that can remove your permitted development rights
Even when your project fits within a Class, the property itself can disqualify it. The six main disqualifiers:
- 1. Listed building status. All external work needs listed building consent regardless of size, and most Class B and Class C rights are removed entirely. Interior changes can also need consent depending on what’s being altered.
- 2. Conservation areas. Class A side extensions and exterior cladding are removed, and rear extensions have tighter dimension limits. Class B loft conversions are removed entirely. Councils publish a character appraisal for each conservation area that guides the design of anything that does need planning permission.
- 3. Article 4 Directions. Councils can withdraw specific permitted development rights in a defined area on a case-by-case basis. Common examples: removing the right to replace original windows, paint external brickwork, or pave over front gardens.
- 4. Designated land. National Parks, Areas of Outstanding Natural Beauty (AONBs / National Landscapes), World Heritage Sites, and The Broads all reduce PD rights under Article 2(3). Dimension limits are typically halved, cladding rights are removed, and side extensions are restricted.
- 5. Flood zones. Properties in flood zones 2 and 3 have restricted rights for certain outbuilding classes and may need a Flood Risk Assessment alongside any planning application.
- 6. The 50% curtilage rule. Permitted development is cumulative. If previous extensions or outbuildings have used up too much of the original curtilage, you can’t add more under PD — you’ll need a full application.
How to prove your work is lawful
One thing to understand about permitted development: there’s no automatic stamp of approval. If you build within the rules, your work is lawful, but you don’t get any paperwork saying so. That becomes a problem when you try to sell the property — the buyer’s solicitor will ask for evidence that any extensions were lawful, and “I checked and I was sure” isn’t good enough.
The answer is a Lawful Development Certificate. You apply to your council for a Certificate of Lawful Use or Development, either before you build (“proposed”) or after (“existing”), and if your work meets the rules, the council issues a legally binding certificate confirming the development is lawful. It takes about 8 weeks and the fee is currently £129 for a proposed-use certificate.
An LDC is the gold standard for proving permitted development. We generate a free LDC application pack with a full supporting statement based on your specific project and property.
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Frequently asked questions
What are permitted development rights?
Permitted development rights are a set of national rules — the General Permitted Development Order 2015 (GPDO) — that let homeowners carry out certain types of work without applying to their council for planning permission. If your project fits within the rules, you don’t need a formal application. The rights are grouped into numbered classes: Class A for house enlargements, Class B for loft conversions, Class C for roof alterations, and so on.
What is the GPDO?
GPDO stands for the General Permitted Development Order. The current version is the Town and Country Planning (General Permitted Development) (England) Order 2015, as amended. It’s the single piece of secondary legislation that sets out all permitted development rights in England. Scotland and Northern Ireland have their own separate GPDOs.
Do I have permitted development rights on a flat?
No. Most Class A rights only apply to houses — detached, semi-detached, terraced, and end-of-terrace. Flats and maisonettes don’t have the right to extend under permitted development. Any external alteration to a flat typically requires a full planning application.
What’s an Article 4 Direction?
An Article 4 Direction is a tool councils use to withdraw specific permitted development rights in a defined area — often a single street or a cluster of streets. They’re common in London conservation areas where councils want tighter control over things like front-door replacements, window alterations, and external cladding. If your property is covered by an Article 4 Direction, you’ll need planning permission for the specific types of work it restricts, even if those works would normally be permitted development elsewhere.
What is “designated land”?
Designated land is a term defined in Article 2(3) of the GPDO. It covers National Parks, Areas of Outstanding Natural Beauty (AONBs, now called National Landscapes), World Heritage Sites, and The Broads. Properties on designated land have reduced permitted development rights — for example, the maximum volume a rear extension can add is typically halved, cladding rights are removed, and side extensions are restricted.
How does the 50% curtilage rule work?
Permitted development rights for extensions and outbuildings are cumulative across the life of the property. That means if a previous owner already extended the house or added a detached garden building, your allowance shrinks. The total ground area covered by extensions, outbuildings, and similar structures can’t exceed 50% of the original curtilage (the area around the original dwelling as it was in 1948, or when first built if later). Once you hit 50%, no more PD extensions are allowed.