(5) (a) Development by statutory undertakers for the generation, transmission or supply of electricity for the purposes of their undertaking consisting of-�

(1) Standard conditions 1 and 2.

(i)the installation or replacement in, on, over or under land of an electric line and the construction of shafts and tunnels and the installation or replacement of feeder or service pillars or transforming or switching stations or chambers reasonably necessary in connection with an electric line;

(2) in the case of any sub-paragraph (a)(i) development consisting of or including the replacement of an existing electric line, any conditions contained in a planning permission relating to the height, design or position of the existing electric line which are capable of being applied to the replacement line;

(ii)the installation or replacement of any telecommunications line which connects any part of an electric line to any electrical plant or building, and the installation or replacement of any support for any such line;

(3) in the case of any sub-paragraph (a)(i) development consisting of or including the installation of a temporary electric line providing a diversion for an existing electric line, on the ending of the diversion or at the end of a period of six months from the completion of the installation (whichever is the sooner) the temporary electric line shall be removed and the land on which any operations have been carried out to install that line shall be restored as soon as reasonably practicable to its condition before the installation took place;

(iii)the sinking of boreholes to ascertain the nature of the subsoil and the installation of any plant or machinery reasonably necessary in connection with such boreholes;

(4) in the case of any sub-paragraph (a)(i) development consisting of or including the installation of a temporary electric line providing a diversion for an existing electric line, on the ending of the diversion or at the end of a period of six months from the completion of the installation (whichever is the sooner) the temporary electric line shall be removed and the land on which any operations have been carried out to install that line shall be restored as soon as reasonably practicable to its condition before the installation took place;

(iv)the extension or alteration of buildings on operational land of the undertaking;

(v)the erection on operational land of the undertaking of a building solely for the protection of plant or machinery;

(vi)any other development carried out in, on, over or under the operational land of the undertaking.

(b)Development is not permitted by this class if-�

(i)in the case of any sub-paragraph (a)(i) development-�

(aa)it would consist of or include the installation or replacement of an electric line to which section 37(1) of the Electricity Act 1989(4) applied; or

(bb)it would consist of or include the installation or replacement at or above ground level or under a road used by vehicular traffic, of a chamber for housing apparatus and the chamber would exceed 29 cubic metres in capacity;

(ii)in the case of any sub-paragraph (a)(ii) development-�

(aa)the development would take place in a national scenic area, or a site of special scientific interest;

(bb)the height of any support would exceed 15 metres; or

(cc)the telecommunications line would exceed 1000 metres in length;

(iii)in the case of any sub-paragraph (a)(iv) development-�

(aa)the height of the original building would be exceeded;

(bb)the cubic content of the original building would be exceeded by more than 25%; or

(cc)the floorspace of the original building would be exceeded by more than 1000 square metres;

(iv)in the case of any sub-paragraph (a)(v) development, the building would exceed 15 metres in height; or

(v)in the case of any sub-paragraph (a)(vi) development, it would consist of or include-�

(aa)the erection of a building, or the reconstruction or alterations of a building where its design or external appearance would be materially affected; or

(bb)the installation or erection by way of addition or replacement of any plant or machinery exceeding 15 metres in height or the height of any plant or machinery replaced, whichever is the greater.

(c)(i)For the purpose of sub-paragraph (a)(i) "electric line" has the meaning assigned to that term by section 64(1) of the Electricity Act 1989.

(ii)For the purpose of sub-paragraph (a)(ii) "electrical plant" has the meaning assigned to that term by the said section 64(i) and "telecommunication line" means a wire or cable (including its casing or coating) which forms part of a telecommunications apparatus within the meaning assigned to that term by paragraph 1 of Schedule 2 to the Telecommunications Act 1984(5).

(iii)For the purposes of sub-paragraph (a)(iv), (v) and (vi) the land of the holder of a licence under section 6(2) of the Electricity Act 1989 shall be treated as operational land if it would be operational land within section 211 of the Town and Country Planning (Scotland) Act 1972 if such licence holders were statutory undertakers for the purpose of that section.

(5A) Development for which consent has been granted by the Secretary of State under the Electricity Act 1989(6) provided that-�

(i)such development shall be permitted only to the extent specified in the consent;

(ii)such development shall not be permitted by this order unless the undertaker has, on or before the date of application for consent, notified the general or district planning authority of the application and has furnished the Secretary of State with a statement that this has been done."