Sheds sold as needing no permission: checking the claim

When a garden building supplier says no planning permission is needed, they are describing their product, not your garden. The claim is usually accurate about the building in isolation and silent about the three things that decide the question: where it will stand, how tall it will be at that position, and how much of the garden is already covered. A supplier cannot know any of those, and their statement has no legal standing if the council disagrees.

Class E of Part 1 of Schedule 2 to the General Permitted Development Order 2015 is the right in question. It permits buildings, enclosures, pools and containers within the curtilage of a dwellinghouse required for a purpose incidental to the enjoyment of the dwellinghouse. Every word of that does work.

Why a supplier's statement is not a determination

The only bodies that determine whether something is permitted development are the local planning authority, on an application for a lawful development certificate, and on appeal the Planning Inspectorate.

A brochure claim is a description of a standard specification against the general limits. It cannot account for a corner plot where two elevations front a highway, a garden that already has a large garage, a conservation area boundary running through the street, or a condition on the 1998 estate permission removing Class E rights entirely.

That last one is more common than people think. Developers of new estates are frequently required to accept conditions removing permitted development rights, and those conditions run with the land for the life of the permission.

The three limits a garden building usually breaches

Height comes first, and it is measured from the highest ground level adjacent to the building, not from the floor slab or from where you are standing.

The limits under Class E are 4 metres for a dual-pitched roof, 3 metres for anything else, and 2.5 metres for any building where any part is within 2 metres of the boundary of the curtilage. Since most garden buildings are placed against a fence, the 2.5 metre figure is the one that applies to most of them.

Second, ground coverage. The right is lost if the total area of ground covered by buildings, enclosures, containers and pools within the curtilage, other than the original dwellinghouse, would exceed 50 per cent of the curtilage excluding the ground area of the original house. Existing sheds, a garage, a greenhouse and a hot tub enclosure all count towards that. On a small terraced garden with an existing outbuilding, a new garden room can tip it over.

Third, position. Nothing may be situated on land forward of a wall forming the principal elevation of the original dwellinghouse. On a corner plot this bites hard, and the wall in question is the one on the original house, not on an extension added since.

Eaves height and the 2 metre boundary test

The 2 metre boundary test catches more garden rooms than any other provision, because the modern flat-roofed garden office is usually between 2.5 and 3 metres tall and is almost always placed at the end of the garden against the fence.

Measure to the boundary of the curtilage, not to the fence panel if the fence is not on the boundary, and measure from the nearest part of the building including any overhang. A 2.7 metre high building 1.9 metres from the boundary is outside the right. The same building 2.1 metres from the boundary is inside it, subject to everything else.

Eaves height is capped at 2.5 metres in all cases. On a dual-pitched building that allows a ridge up to 4 metres provided the eaves stay low and the building is more than 2 metres from any boundary.

Verandas, balconies and raised platforms are excluded from the right altogether, and a raised platform includes a decked area more than a modest height above the ground. A garden room reached by a small deck can lose its permitted development status because of the deck rather than the building.

Internal fit out and the incidental test

The right applies to a building required for a purpose incidental to the enjoyment of the dwellinghouse. Incidental means subordinate to the residential use of the house, and it is a question of fact.

A home gym, a studio, a hobby room, a store and a home office used by the occupier are ordinarily incidental. What is not incidental is primary living accommodation. A room fitted out with a bed, a kitchen and a shower is accommodation, and providing a separate unit of living accommodation in the garden is a different planning question requiring permission.

Insulation, power and a broadband connection do not by themselves take a building outside the right. Combined with cooking and washing facilities and a bedroom, they do. If the plan is an annexe for a family member, do not try to reach it through Class E.

Running a business from the building is a separate question again. Occasional working is fine; staff, customers visiting, deliveries, signage or vehicle movements can amount to a material change of use of the property.

Designated land and Article 4 areas

On article 2(3) land, which covers conservation areas, National Parks, National Landscapes, the Broads and World Heritage Sites, the right is narrower. Buildings, enclosures, pools and containers situated more than 20 metres from any wall of the house are limited to 10 square metres of ground cover in total.

An Article 4 direction can remove Class E entirely in a defined area. Directions are common in conservation areas and their boundaries do not follow postcodes, so check the direction's own map for the address.

If the house is listed, the curtilage position is tighter again and works may need listed building consent regardless of what Part 1 says. Our note on permitted development rights in a listed building curtilage sets that out, and where the garden has been enlarged from adjoining land the extent of the curtilage itself may be in doubt, as our note on measuring curtilage and the enlarged garden explains.

Check the current text of Class E before relying on any row, since Part 1 has been amended repeatedly.

Consequences of relying on the supplier

If the building turns out to need permission and does not have it, you have an unauthorised development. The council can invite a retrospective application, and can serve an enforcement notice requiring removal if it refuses.

Two further consequences bite later. The building will be raised on a sale, and a buyer's conveyancer will want a certificate or an indemnity policy. And a building close to a boundary that a neighbour objects to is the sort of thing that gets reported, so the risk is not theoretical on a contested boundary.

Supplier contracts rarely give any meaningful remedy. Read what the statement actually promises before treating it as a warranty, and note that any liability is likely to be capped at the price of the building rather than the cost of removing it.

Where the building is large enough to matter, check the Community Infrastructure Levy position as well, since some permitted development can create a liability that has to be declared, as our note on CIL liability and permitted development describes.

Getting the position confirmed

A lawful development certificate for a proposed use or development, under section 192 of the Town and Country Planning Act 1990, is the only formal way to confirm that works are lawful. The fee for a proposed certificate is lower than for a full application and is indexed annually, so check the current schedule.

What you submit is a site plan showing the curtilage and the position of the building, a drawing with dimensions including heights to eaves and ridge, a plan of the existing outbuildings with their footprints, and a short statement applying the Class E limits to each of them.

Illustrative example: a 3.6 metre by 4.2 metre garden office with a flat roof at 2.8 metres, proposed 1.5 metres from the rear boundary of a semi-detached house. The supplier's brochure says no permission needed. At that distance from the boundary the height limit is 2.5 metres, so it is outside Class E. Moving it 600 millimetres forward brings it inside, and the certificate confirms it.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.

Enter your postcode on PlanScope to see which documents a certificate application for a garden building is likely to need.