15.—(1) The employer shall ensure that rope access and positioning techniques are not used for work at height unless—
(a)the application of the regulation 8 criteria has demonstrated that—
(i)the work can be performed safely; and
(ii)the use of safer work equipment is not justified; and
(b)the provisions of Schedule 3 are complied with.
(2) Where rope access and positioning techniques are used for work at height, the employer shall provide the worker with a seat with appropriate accessories if it is appropriate to do so in the light of application of the regulation 8 criteria and, in particular, the duration of the task and the ergonomic constraints under which the worker will be working.