The equations goving wind-induced intal pressure responses for a two-compartment building with a dominant opening and background porosity were derived.The unsteady form of the Boulli equation,the law of mass conservation,and adiabatic equation were used for the derivation.The precision of the goving equations was verified by a wind tunnel test on a rigid model of a low-rise building.The results show that the goving equations can effectively analyze the wind-induced intal pressure responses.The intal pressure responses in both compartments are suppressed due to the additional damping provided by background porosity.The responses of intal pressure in both compartments,especially in the compartment without an extal opening,decrease with increased lumped leakage area.