The potential for utilization of the building mass thermal capacity for demand side management in the residential sector is addressed. A three apartment residential houses made of massive brick, equipped with a heat pump is modeled and its thermal behavior is simulated. It is shown that thermal storage capacity of the building can indeed contribute considerably to residential demand side management activities. Even after heating periods as short as two hours the heating demand for the following four hours can be reduced by almost 20 %. The slow temperature increase within the thermal mass and the heat conduction into deeper wall layers are thereby the main limiting factors.