A structure designed or adapted for human habitation which—
shall not be treated as not being (or as not having been) a caravan within the meaning of Part I of the Caravan Sites and Control of Development Act 1960 by reason only that it cannot lawfully be so moved on a highway road when assembled.
For the purposes of Part I of the Caravan Sites and Control of Development Act 1960, the expression "caravan" shall not include a structure designed or adapted for human habitation which falls within paragraphs (a) and (b) of the foregoing subsection if its dimensions when assembled exceed any of the following limits, namely—
The Minister Secretary of State may by order made by statutory instrument after consultation with such persons or bodies as appear to him to be concerned substitute for any figure mentioned in subsection (2) of this section such other figure as may be specified in the order.
Any statutory instrument made by virtue of subsection (3) of this section shall be subject to annulment in pursuance of a resolution of either House of Parliament.