Decision makers that have to decide which type of HVAC system that has to be installed in a building, will usually base their decisions on the investment and running costs (including expected maintenance costs) and their perception of the quality of the system. In general, the energy savings will be compared to a reference (less efficient) system to calculate the benefit. However, the choice of the building equipment has also an impact on the Indoor Environmental Quality (IEQ) and on the performance of the workers inside the building. This is frequently forgotten, probably because they do not pay attention and because the IEQ is difficult to assess and to convert into money, whereas energy can easily be converted. For the HVAC world, it is important to increase the awareness on this problem. That's why AIVC considered that the present report, written in the framework of the IEA HYBVENT project, would be a valuable Contributed Report. As its name indicates ("Considerations concerning costs and benefits with application to ventilation"), the report does not aim to be an exhaustive guide on the topic, but aims to give background information of the subject.