4. The following activities carried on at any premises by persons who do not normally work in the premises—
(a)construction work if—
(i)regulation 7(1) of the Construction (Design and Management) Regulations (Northern Ireland) 1995(1) (which requires projects which include or are intended to include construction work to be notified to the Department) applies to the project which includes the work;
(ii)the whole or part of the work contracted to be undertaken by the contractor at the premises is to the external fabric or other external part of a building or structure; or
(iii)it is carried out in a physically segregated area of the premises, the activities normally carried out in that area have been suspended for the purpose of enabling the construction work to be carried out, the contractor has authority to exclude from that area persons who are not attending in connection with the carrying out of the work and the work is not the maintenance of insulation on pipes, boilers or other parts of heating or water systems or its removal from them;
(b)the installation, maintenance or repair of any gas system, or any work in relation to a gas fitting;
(c)the installation, maintenance or repair of electricity systems;
(d)work with ionising radiations except work in one or more of the categories set out in Schedule 3 to the Ionising Radiations Regulations (Northern Ireland) 1985.