25. (1) For the purposes of this article and the Fifth Schedule,—

(a) “relevant floor area” means the floor area of the works or the building to which the application relates which is affected by the works or the material change of use, as the case may be;

“floor area” means the sum of the areas on each floor bounded by the inner finished surfaces of the enclosing walls, or, on any side where there is no enclosing wall, by the outermost edge of the floor on that side, and, in calculating the floor area of a building, there shall be included in such area the space occupied by any walls, shafts, ducts or structure within the area being measured.

(b) in determining the fee payable in respect of a commencement notice, a house in a terrace and a semi-detached house are each to be treated as being a separate building.

(2) Where the floor area or the relevant floor area referred to in sub-article (1) is not an exact multiple of that unit, the fraction of a unit remaining after the division of the total area by the unit measurement shall be treated, for the purposes of calculating the fee payable in respect of the application, as a complete unit.

F56[(3) Where an application for a fire safety certificate, a revised fire safety certificate, a regularisation certificate, a disability access certificate, a revised disability access certificate or the submission of a 7 day notice includes alternative proposals for works or a building of materially different designs, the fee payable in respect of the application shall be calculated as if each alternative proposal were a separate application or a separate 7 day notice.]