This paper presents the results of the activities related to the subtask “Building and process optimization” of the IEA SHC Task 65. The main topic of this activity was the integration of solar cooling in retrofitted HVAC systems. Based on the current conventional HVAC systems, the integration may present difficulties concerning cold distribution and refrigerants. Cold supply systems can also reduce airflow in air-based systems and enhance thermal comfort in buildings. The best technical actions for specific scenarios were mentioned considering both technical and economic aspects. Unfortunately, not all the analyses that were planned provide useful data. Results show that there are few recent projects that consider the application of solar cooling systems in buildings and most of them are based on simulation. Moreover, not much data about the characteristics of the buildings (envelope, other cooling systems, comfort conditions, etc.) are reported in the studies. This is because many of them are more focused on the plants’ configurations, and the performance of the different plants is in general assessed by testing the prototype in a single room. Despite this, the information provided could be used as baseline cases in order to study the potential energy savings achievable by applying solar cooling systems.