Definition: Listed Building
"...means a building which is for the time being included in a list compiled or approved by the Secretary of State under this section; and for the purposes of this Act -
(a) any object or structure fixed to the building;
(b) any object or structure within the curtilage of the building which, although not fixed to the building, forms part of the land and has done so since before 1st July 1948,
shall subject to subsection (5A)(a) be treated as part of the building."