This paper gives some results of computer simulations of the thermal performance of three types of passive solar systems - direct gain, collector storage wall and attached sunspace - in three locations of temperate Australia. The heat transfer processes that occur in these systems have been incorporated into ZSTEP3, a program for dynamically simulating the thermal performance of multizone buildings, based on the total-zone response factor method. The systems are simulated as part of a compact three-bedroom house that has auxiliary intermittent heating to the living zone only, and no artificial cooling, typical for temperate Australia. Evaluation is in terms of annual living zone energy requirements and degree of overheating in summer. The results show that all three systems can perform well in winter and summer, provided that they are well-shaded.