The aim of this study was to analyse how energy use, building physics properties and indoor environment data have been obtained in the initial evaluation phases of multifamily building renovations in Sweden. Between 1964 and 1975, approximately one million homes were built in Sweden. These buildings are now in need of renovation. To perform proper status assessment of a building before a renovation is important both to make decisions on renovation measures on correct information as well as to be able to perform follow-ups of renovation projects. The analyses in this study was performed with questionnaires in eight case studies. Studied data included energy use, building physics properties and indoor environmental factors. The study shows that information about a building’s status, and the subsequent renovation process, is often linked to one or just a few people involved in the project without any systematic documentation. When they leave their employment, due to changing jobs or retirement, documentation about the condition of the building, material choices and decision processes is often lost.