Works for the alteration or extension of a listed building are authorised if—
written consent for their execution has been granted by the local planning authority or the Secretary of State; and
they are executed in accordance with the terms of the consent and of any conditions attached to it.
Works for the demolition of a listed building are authorised if—
such consent has been granted for their execution;
notice of the proposal to execute the works has been given to the Royal Commission;
after such notice has been given either—
for a period of at least one month following the grant of such consent, and before the commencement of the works, reasonable access to the building has been made available to members or officers of the Royal Commission for the purpose of recording it; or
the Secretary of the Royal Commission, or another officer of theirs with authority to act on their behalf for the purposes of this section, has stated in writing that they have completed their recording of the building or that they do not wish to record it; and
the works are executed in accordance with the terms of the consent and of any conditions attached to it.
Where—
works for the demolition of a listed building or for its alteration or extension are executed without such consent; and
written consent is granted by the local planning authority or the Secretary of State for the retention of the works,
the works are authorised from the grant of that consent.
In this section "the Royal Commission" means—
... the Royal Commission on the Historical Monuments of England; and
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The Secretary of State may by order provide that subsection (2) shall have effect with the substitution for the references to the Royal Commission of references to such other body as may be so specified.
Such an order—
shall apply in the case of works executed or to be executed on or after such date as may be specified in the order; ...
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Consent under subsection (1), (2) or (3) is referred to in this Act as "listed building consent".