The promoter, so far as is reasonably practicable, must exercise the powers conferred by article 18 (safeguarding works to buildings) so as not to obstruct or render less convenient the access to any apparatus.

The promoter must not, in the exercise of the powers conferred by section 11(3) (powers of entry) of the 1965 Act, as applied by this Order, or by article 20 (power to survey and investigate land, etc.), make any trial holes which interfere with any apparatus without the consent of the specified undertaker (which must not be unreasonably withheld).