Section 177 Validity of enforcement notices and similar notices
Subject to the next following subsection, the validity of an enforcement notice which has been served under Part IV of this Act on the owner and occupier of the land shall not, except by way of an appeal under Part IV of this Act, be questioned in any proceedings whatsoever on any of the grounds specified in paragraphs (b) to (e) of subsection (1) of section forty-six of this Act.
The preceding subsection shall not apply to proceedings brought under subsection (5) of section forty-seven of this Act against a person who—
has held an interest in the land since before the enforcement notice was served under Part IV of this Act, and
did not have the enforcement notice served on him thereunder, and
did not appeal against that notice under Part IV of this Act.
The validity of a notice which has been served under section fifty-two of this Act on the owner and occupier of the building to which the notice relates shall not, except by way of an appeal under Part IV of this Act, be questioned in any proceedings whatsoever on the grounds that the works to which the notice relates were not, or were not wholly, works in contravention of subsection (1) of section thirty-three of this Act.
Subject to the next following subsection, the validity of a notice which has been served under section thirty-six of this Act on the owner and occupier of the land shall not, except by way of an appeal under Part IV of this Act, be questioned in any proceedings whatsoever on any of the grounds specified in paragraphs (a) to (c) of subsection (1) of section fifty-seven of this Act.
The last preceding subsection shall not apply to proceedings brought under section fifty-six of this Act against a person on whom the notice referred to in that subsection was not served, but who has held an interest in the land since before that notice was served on the owner and occupier of the land, if he did not appeal against the notice under Part IV of this Act.
The validity of a notice purporting to be an enforcement notice shall not depend on whether any non-compliance to which the notice relates was a non-compliance with conditions, or with limitations, or with both; and any reference in such a notice to non-compliance with conditions or limitations (whether both expressions are used in the notice or only one of them) shall be construed as a reference to non-compliance with conditions, or with limitations, or both with conditions and limitations, as the case may require.