Building with an installation for forced ventilation and at least one room forcibly ventilated by said installation, and a wall structure of said forcibly ventilated room comprising an exterior wall with at least two contiguous construction elements (5a, 5b), particularly a construction element providing a wall embrasure and at least one frame profile, wherein a joint is formed between said two construction elements (5a, 5b), and comprising at least one sealing tape which is disposed in a compressed manner within said joint between said two constructions elements (5a, 5b), particularly between said frame profile and said wall embrasure, wherein the sealing tape comprises a body from a compressible and restorable foam material and the sealing tape has two opposing broadsides (B1, B2) that can be respectively applied against an abutting surface of said two construction elements, wherein preferably a first one of said broadsides is provided with a fixing means (Bf) by means of which the sealing tape can be fixed or adhered to the corresponding abutting surface of the construction element, and wherein two opposing narrow sides (S1, S2) extending transversely to said broadsides are provided, namely one towards the outside of the room and one towards the inside of the room, characterized in that the forced ventilation is adjusted in such a manner that the passage of air through said joint which is sealed with said sealing tape amounts to at least 1 liter per meter length of the joint and per hour, in accordance with DIN 18542, extrapolated to a pressure difference of 10 Pa, and the sealing tape is constructed in such a manner that, when the sealing tape is arranged in a compressed state within the joint, both narrow side regions have different vapor diffusion resistances, and the narrow side region of the sealing tape facing the outside of the room has a higher vapor barrier effect then the opposing narrow side region facing the inside of the room, and the vapor diffusion resistance increasing means (P, St, DN1, DB2, PL, F3, ML) causes an increased driving rain impermeability resistance and/or UV resistance and/or a decreased air permeability of the joint compared to the opposing narrow side of the sealing tape, and that (i) in the region of the narrow sides having the increased vapor barrier effect, the foam material has a higher material density which increases over the width of the band from the narrow side facing the inside of the room towards the narrow side facing the outside of the room or that (ii) said increased vapor barrier effect is produced by a coating in the region of the narrow side which has the increased vapor barrier effect or by a film covering one of the narrow sides of the sealing tape on the external side thereof or that (iii) said increased vapor barrier effect is obtained by a film or a coating layer arranged in an incision or cut-through of the cross sectional area of the sealing tape. (i) in the region of the narrow sides having the increased vapor barrier effect, the foam material has a higher material density which increases over the width of the band from the narrow side facing the inside of the room towards the narrow side facing the outside of the room or that (ii) said increased vapor barrier effect is produced by a coating in the region of the narrow side which has the increased vapor barrier effect or by a film covering one of the narrow sides of the sealing tape on the external side thereof or that (iii) said increased vapor barrier effect is obtained by a film or a coating layer arranged in an incision or cut-through of the cross sectional area of the sealing tape.