xmlns:atom="http://www.w3.org/2005/Atom"
1. A detached single storey building, having a floor area which does not exceed 30m2, which contains no sleeping accommodation and is a building—
(a)no point of which is less than one metre from the boundary of its curtilage; or
(b)which is constructed substantially of non-combustible material.
2. A detached building designed and intended to shelter people from the effects of nuclear, chemical or conventional weapons, and not used for any other purpose, if—
(a)its floor area does not exceed 30m2; and
(b)the excavation for the building is no closer to any exposed part of another building or structure than a distance equal to the depth of the excavation plus one metre.
3. A detached building, having a floor area which does not exceed 15m2, which contains no sleeping accommodation.