21. Whether the living accommodation occupied by the household to which the return relates is a—
(a)whole house or bungalow (and whether detached, semi-detached or terraced (including end-terrace));
(b)flat, maisonette or apartment (and whether in a purpose-built block of flats or tenement, part of a converted or shared house (including bed-sits) or in a commercial building); or
(c)caravan or other mobile or temporary structure.