25. A specified work shall be constructed (and in the case of any temporary work removed) only in accordance with—
(a)the approved plans (and, in the case of plans relating to sewers approved, deemed to have been approved or settled by arbitration, as amended from time to time by agreement between the promoter and the specified undertaker); and
(b)all reasonable requirements made by the specified undertaker for the alteration, or otherwise for the protection, of the apparatus, or for securing access to it,
and the specified undertaker shall be entitled by its officer to watch and inspect the carrying out of the work.