Development is not permitted by Class A(a) if, in the case of the installation, alteration or replacement of apparatus (other than an antenna) on a mast, the height of the mast would, when the apparatus was installed, altered or replaced, exceed any relevant height limit specified in respect of apparatus in paragraphs A.1(1)(a), (b) and (c), and A.1(2)(a) and (b), and for the purposes of applying the limit specified in paragraph A.1(2)(a), the words “(taken by itself)” in that paragraph are omitted.