4.—(1) For the purposes of Class 7(2)—
“aggregate number” means the aggregate of the number of houses constructed, in the course of construction or proposed to be constructed on the land concerned;
“flat” means a separate and self-contained set of premises constructed for use for the purpose of a dwelling and forming part of a building from some other part of which it is divided horizontally;
“house” includes a flat;
“planning permission” does not include any outline planning permission in relation to which some or all of the matters reserved for subsequent approval remain to be approved; and
“the land concerned”, in relation to any development, means—
except in a case to which sub-paragraph (2) or (3) applies, the land to which the planning permission for the development relates;
in a case to which sub-paragraph (3) applies, the land on which a particular phase of that development was, or as the case may be, is being or is about to be carried out;
in a case to which sub-paragraph (3) applies, the part of the land to which the permission relates on which a person has carried out part of that development, or as the case may be, is carrying it out or is about to carry it out.
(2) Subject to sub-paragraph (3), this sub-paragraph applies where the development is carried out in phases.
(3) This sub-paragraph applies where the development is carried out by two or more persons who each carry out part of it on a discrete part of the land to which the planning permission relates (whether the whole of the development or any part of it is carried out in phases or otherwise).