Solar-based poly-generation systems with thermally driven sorption heat pump / chillers use the condensation heat of ORC to cover heating and cooling loads of buildings. In the present study the performance of such systems when used in buildings in the Netherlands and Greece is investigated taking both exergy efficiency and economic aspects into account. The alternative of using PV-panels and electrically driven vapour compression heat pumps / chillers is also investigated. The performance of the systems is compared to the performance of conventional heating and cooling systems. Higher exergy efficiencies can be attained with the ORC sorption systems only for unacceptably long payback times. Optimum systems will have low exergy efficiency (8 %) compared to the exergy efficiency of conventional systems (16 %) and still long payback times (longer than 19 years). PV - panel vapour compression heat pump / chiller systems have generally acceptable payback times smaller than 10 years.