Not much is known about the favourable indoor air conditions in long term care facilities (ltcf’s), where older adults suffering from dementia live. Due to the decrease in cognition function, it is hard to evaluate comfort and health in this group. Nevertheless, infectious diseases are a persistent problem. Based on literature an assessment method has been developed to analyse ltcf’s to determine if differences in building characteristics and HVAC systems influence the spread of airborne infectious diseases. The developed method is applied in seven long term care facilities in the Netherlands. From this research it can be concluded that this method has potential to evaluate and compare ltcf’s and develop design guidelines for these buildings. However, some adjustments to the methodology are necessary to achieve this objective. Therefore the relation between the indoor environment and infection risk is not yet analysed, but a consistent procedure to analyse this link is provided.