Horse-box production method using pre-fabricated modules

A method of equipping a volume wherein interior surfaces (floor, walls, ceiling), decorations, fixtures and/or fittings are constructed as a module which includes one or more horizontally movable structures 405, 406 comprising at least one rigid side wall - one of the structures further comprising a substantially vertical partition wall affixed to the at least one rigid side wall. The module is inserted into a pre-existing outer shell 401 defining an outer volume. The outer shell and horizontally movable structure(s) form a telescopic arrangement which allows for variable partitioning between two compartments equipped for different purposes - e.g. a horsebox with separate living accommodation. The volume may be used for transporting horses, bicycles or other goods, or may be a shipping container or room within a building. A portion of the module may open to provide access to a further portion of the outer volume. Outer faces of the module may be exposed or covered with a transparent sheeting to allow installation of fixtures and fittings.