1.—(1) In this Schedule and in Schedule 9—
“commencement” means the carrying out of a material operation, as defined in section 155 of the 2008 Act (which explains when development begins), comprised in or carried out for the purposes of the authorised development and the words “commence” and “commenced” are to be construed accordingly;
“stage” refers to—
the stage of the authorised development comprising works in the vicinity of the permitted substation (including underground ducting and highway access); and
the stage comprising the remainder of the authorised development in Schedule 1 unless otherwise approved by the relevant planning authority.
(2) Where any Requirement specifies: “unless otherwise approved in writing” by the relevant planning authority; or “unless otherwise agreed in writing” with the relevant planning authority; such approval or agreement must not be given except in relation to minor or immaterial changes where it has been demonstrated to the satisfaction of the relevant planning authority that the subject-matter of the approval or agreement sought is unlikely to give rise to any materially new or materially different environmental effects from those assessed in the environmental document.