For the purposes of this Act "dwelling" means a dwelling which is ... in Wales, and—
(a) does not include any structure or vehicle which is capable of being moved from one place to another, but
(b) includes any land occupied together with the dwelling, unless the land is agricultural land exceeding 0.809 hectares.
"Agricultural land" means—
(a) land used as arable, meadow or pasture ground only;
(b) land used for a plantation or a wood or for the growth of saleable underwood;
(c) land used for the purpose of poultry farming, market gardens, nursery grounds, orchards or allotments, including allotment gardens within the meaning of the Allotments Act 1922 (c. 51),
but does not include land occupied together with a house as a park, gardens (other than as mentioned in paragraph (c)) or pleasure grounds, land used mainly or exclusively for purposes of sport or recreation or land used as a racecourse.
Dwelling, in relation to an occupation contract, means the dwelling subject to the contract.