Abstract: A method of assembling an apparatus (1) for heating aerosolisable material to volatilise at least one component of the aerosolisable material to form an aerosol for inhalation by a user, the apparatus having a first proximal end (3) and a second distal end (5), the method comprising the steps of providing a first chassis (19) for supporting a heating arrangement for receiving and heating aerosolisable material, the first chassis (19) or a component supported by the first chassis (19) comprising a first engagement element; providing a first sleeve (11b) to form at least a part of a casing of the apparatus, the first sleeve (11b) comprising a second engagement element; and inserting the first chassis (19) into a cavity of the first sleeve (11b) to cause automatic engagement of the first engagement element and the second engagement element during assembly of the apparatus (1).