(1)

(a) In this section, "qualifying premises" means a building or structure the site of which is wholly within a designated area, or which fronts on to a designated street, and which -

(i) apart from this section is not an industrial building or structure within the meaning of section 268, and

(ii)

(I) is in use for the purposes of a trade or profession, or

(II) whether or not it is so used, is let on bona fide commercial terms for such consideration as might be expected to be paid in a letting of the building or structure negotiated on an arm's length basis,

but does not include any part of a building or structure in use as or as part of a dwelling house or an office.

(b) Notwithstanding paragraph (a) -

(i) in relation to a building or structure no part of the site of which is within any one of the county boroughs of Dublin, Cork, Limerick, Galway or Waterford, paragraph (a) shall be construed as if "or an office" were deleted;

(ii) where, in relation to a building or structure any part of the site of which is within any one of the county boroughs of Dublin, Cork, Limerick, Galway or Waterford, any part (in this paragraph referred to as "the specified part") of the building or structure is not a qualifying premises and -