Reg. 21 in operation at 5.12.2005, see reg. 1
Subject to the following paragraphs an authority may, at any time, vary the conditions attached to an approval under regulation 13(b) on any grounds it thinks fit.
An authority, before proceeding to vary an approval under paragraph (1) shall, no later than 7 days before the day on which the proposed variation is to be considered, notify the approval holder in writing of the proposed variation and shall give that person an opportunity to be heard by the authority on that day or, if preferred by the approval holder, to submit written representations.
An authority shall, within 7 days of its decision under paragraph (1), serve notice of its decision on the approval holder, together with details of the right to a review of the decision under regulation 22.
A variation of an approval shall come into operation—
upon expiry of the period for applying for a review under regulation 22; or
where such an application has been lodged, when the review has been determined in favour of the variation.