Somewhat of a landmark case, the recent ruling in Burford vs Secretry of State in The High Court covers many of the issues we are primarily concerned with at curtilage.co.uk.
Ref: Burford v Secretary of State for Communities and Local Government  EWHC 1493 (Admin)
The appellant had been granted a certificate of lawfulness for use of land within a designated area from Test Valley Borough Council for purposes incidental to the enjoyment of a dwelling house, including the keeping of horses for recreational use. The local authority subsequently issued an enforcement notice identifying a breach of planning control arising from the erection of a building within that area.
The building had been constructed in a level, dug-out area lower than the surrounding sloping ground. The appellant challenged the enforcement notice on the ground that the building was permitted development under the Town and Country Planning (General Permitted Development) (England) Order 2015 Sch.2 Pt 1 because it was within the curtilage of the dwelling and the height of the building's eaves fell within Sch.2 Pt 1 para.E1.
The inspector found that the area in which the building had been erected could not properly be described as curtilage, since it was used for horse paddocks kept separate by fences and hedges from the much smaller garden that constituted the curtilage. He held that, in any event, the appeal would still fail because the height of the eaves, measured from the dugout area around the building, exceeded the 2.5m limit.
It was held that the certificate of lawfulness did not address whether the area it covered was within the curtilage of the dwelling house: it simply certified that the land in question had been used for purposes incidental to the enjoyment of the dwelling house. It did not assist in resolving the question of whether the land containing the building at issue was attached to the dwelling house forming one enclosure with it. Moreover, the inspector had considered the functional relationship between the dwelling house and the land on which the building was constructed.
Whilst the appeal was dismissed, legal principles were held up for the determination of what constitutes curtilage. Three factors had to be taken into account in determining whether a structure or object was within the curtilage of another building:
(a) the physical layout of the building and the other structure;
(b) their ownership, past and present;
(c) their use or function, past and present,
These three criteria for identifying curtilage were originally laid down by the Court of Appeal in Sutcliffe v Calderdale Borough Council in 1982 and this ruling helps solidify those principles
Determining the curtilage was a question of fact and degree: "curtilage" connoted a building or piece of land attached to a dwelling house and forming one enclosure with it: it was not restricted in size, but had to be fairly described as being part of the enclosure of the house to which it referred,