A housing is provided for a motor vehicle HVAC system, which is formed from interconnectable housing parts and has a groove, delimited by a first and a second groove leg, on a first housing part and a tongue on a second housing part and in which to connect the housing parts the tongue is disposed in the groove. In this regard, the first and second groove legs are formed in such a way that in the inserted state of the tongue in the groove at least one groove leg at its free end is spaced apart from a corresponding tongue-side bearing shoulder of the second housing part.