Curtilage: what counts as part of your house

Curtilage is the land immediately around a building that is used with it and serves it. In planning terms it is the ground that goes with the house, which is not the same thing as everything inside your title boundary. There is no definition in the Town and Country Planning Act 1990 or in the General Permitted Development Order, so curtilage is treated as a question of fact and degree, judged on the ground.

That matters more than most homeowners expect. Almost all householder permitted development in the Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 1 applies only to development "within the curtilage of the dwellinghouse". Put a garden office on land that sits outside the curtilage and it needs planning permission, however small and however clearly it belongs to you on paper.

Why curtilage decides what you can build without permission

The permitted development classes in Part 1 are drafted around the dwellinghouse and its curtilage. Class E outbuildings, swimming pools, garden rooms and enclosures must be within the curtilage. The 50 per cent test for Class E is calculated on the area of curtilage excluding the ground area of the original dwellinghouse, so where the curtilage boundary sits changes the arithmetic as well as the principle.

Hard-standing, a dropped kerb across your own front garden, an oil tank, a heat pump under Class G, solar panels on an outbuilding: all of these are framed by curtilage. So a curtilage argument is rarely academic. It usually arrives as an enforcement notice or a refused certificate, months after the building went up.

Curtilage is also distinct from the planning unit. The planning unit is about the extent of a use for change-of-use purposes; curtilage is about the physical extent of land serving a building. A large residential planning unit can contain land that is not curtilage, and councils routinely make that distinction.

No statutory definition, so the courts fill the gap

The starting point is still Sinclair-Lockhart's Trustees v Central Land Board (1950), where curtilage was described as ground used for the comfortable enjoyment of the house and serving its purposes in some necessary or useful manner. Not decorative, not merely owned: used with the house.

The practical test most officers apply comes from Attorney-General ex rel Sutcliffe v Calderdale Borough Council (1983), which looked at three things together:

1. The physical layout of the building and the land, including walls, fences, hedges and levels.
2. Ownership, past and present.
3. Use and function, past and present.

Dyer v Dorset County Council (1989) suggested curtilage would normally be a small area forming part and parcel with the house. That was later qualified in Skerritts of Nottingham Ltd v Secretary of State for the Environment, Transport and the Regions (2000), which confirmed the curtilage of a substantial building need not be small. A manor house can have a large curtilage. A terraced cottage with a long strip garden may not.

Ownership on its own carries little weight. Buying the field behind your garden does not enlarge your curtilage, and neither does mowing it.

Where the line usually falls between garden, paddock and orchard

Enclosure is the single most telling physical feature. If a hedge, wall or post-and-rail fence separates domestic garden from grazing land, officers tend to treat that line as the curtilage boundary, particularly where the land beyond has a separate gate off a lane or has been let for grazing.

Size alone is not decisive, and there is no acreage cut-off. What officers look for is whether the land reads on site as part of the residential unit or as something else that happens to be in the same ownership.

Illustrative example

An illustrative case: a 1930s detached house sits in a 0.2 ha garden, with a stock-fenced 0.6 ha paddock beyond a beech hedge, reached through a five-bar gate. The owner builds a 20 m2 timber studio in the paddock corner and relies on Class E. The council's view is that the paddock is outside the curtilage because it is separately enclosed, has been grazed by a neighbour's ponies and has never been laid out as garden. The studio needs planning permission, and the change of use of that corner of the paddock to residential garden is itself development. The figures here are illustrative rather than drawn from a real decision.

Curtilage of a listed building and the 1948 rule

Section 1(5) of the Planning (Listed Buildings and Conservation Areas) Act 1990 treats any object or structure fixed to a listed building, and any object or structure within its curtilage that forms part of the land and has been there since before 1 July 1948, as part of the listed building. A pre-1948 stable block, coach house, garden wall, privy or gate pier inside the curtilage is therefore listed in its own right for consent purposes, even though it has no separate entry on the National Heritage List for England.

The consequence is blunt. Demolishing or altering that structure without listed building consent is a criminal offence, not a planning breach you can regularise later. Historic England's advice note on listed buildings and curtilage is the standard reference, and it stresthat curtilage for listing purposes is judged at the date of listing, using the same physical, ownership and functional factors.

Permitted development rights are also narrower here. Several Part 1 classes are restricted or removed on land within the curtilage of a listed building and on Article 2(3) land, which covers conservation areas, National Landscapes, National Parks, the Broads and World Heritage Sites. Where heritage is engaged, the council will expect a Heritage Statement explaining the significance of the affected structures and the effect of the works.

Bringing a field into your curtilage

Turning agricultural land into residential garden is a material change of use under section 55 of the 1990 Act. It needs planning permission. Councils in the Green Belt and in National Landscapes often resist garden extensions because domestic paraphernalia, fencing, lighting and hard-standing erode open character, and refusals on that basis are common.

Two things follow for anyone planning ahead:

• Apply for the change of use of the land first, or apply for the building and the land use together in one full application. A single application describing both avoids the trap of a lawful building on unlawful land.
• Do not assume time cures it. Enforcement time limits in England were revised by the Levelling-up and Regeneration Act 2023, and the position depends on when the breach occurred, so check the current rules with your local planning authority rather than relying on an old four-year rule of thumb.

A short Planning Statement setting out the site's history, the extent of the existing curtilage and the policy case for the extension is usually the difference between an officer understanding the proposal and an officer refusing it as an unjustified encroachment into open countryside.

Evidence that settles a curtilage argument

When the council disagrees with you, the argument is won with documents rather than adjectives. Assemble:

• Historic Ordnance Survey maps, ideally showing the layout before 1948 for listed building questions.
• Aerial photography over several decades, showing enclosures, mown lawn, hard-standing and field boundaries.
• Earlier planning permissions and their approved plans, especially any red line and blue line boundaries.
• Conveyance plans and title plans, remembering these show ownership rather than curtilage.
• Dated photographs of walls, hedges, gates and levels, taken from positions marked on a plan.
• Statutory declarations from previous owners or long-standing neighbours about how the land was used.

The only formal way to confirm that works are lawful is a Lawful Development Certificate: section 191 of the 1990 Act for existing development and section 192 for proposed development. A section 192 certificate before you build is far cheaper than defending an enforcement notice afterwards, and the application forces the council to state its view of the curtilage in writing.

One honest uncertainty: two officers can look at the same hedge and reach different conclusions, and appeal inspectors have gone both ways on similar facts. Those decisions are indicative of how the tests are applied, not binding precedent.

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. If you want to see what a curtilage question means for your documents, enter your postcode on PlanScope and check which reports your site is likely to need.