4.—(1) An application for the grant of an environmental permit under regulation 13(1) for a relevant installation which forms part of a new district heating and cooling network or existing district heating or cooling network, must contain a cost-benefit analysis.
(2) The regulator must exercise its relevant functions to ensure that an application for a variation of an environmental permit under regulation 20(1) is made before the energy plant of a relevant installation which forms part of a district heating and cooling network is substantially refurbished.
(3) An application for the variation of an environmental permit required by sub-paragraph (2) must contain (in addition to the information required by paragraph 2(1)(b) of Schedule 5) a cost-benefit analysis.
(4) The cost-benefit analysis required by sub-paragraphs (1) and (3) must include an assessment of the cost and benefits of utilising the waste heat from nearby installations.