(1)In this Part of this Act—
“dwelling-house” includes any building or part thereof which is used as a dwelling;
“mortgage” includes a charge and “mortgagor” and “mortgagee” shall be construed accordingly;
“mortgagor” and “mortgagee” includes any person deriving title under the original mortgagor or mortgagee.
(2)The fact that part of the premises comprised in a dwelling-house is used as a shop or office or for business, trade or professional purposes shall not prevent the dwelling-house from being a dwelling-house for the purposes of this Part of this Act.