The Leibniz-Institute of Ecological and Regional Development (IOER) is a non-profit research institute that is active in the areas of documentation, evaluation and communication of environmental properties of buildings. Two of the key terms in this context are ‘environmental labelling for buildings’ and ‘building passport’. The term ‘building passport’ is currently being used with differing meanings. The political debate in general tends to promote private building passport schemes and services as a voluntary measure, very supportive of high-quality construction. It may denote a two-page certificate displaying the most important performance characteristics and technological data of a building – comparable with motor-vehicle documents – as well as a comprehensive collection of various building-related documents (plans, calculations, lists and declarations of materials and products for regulating the operation and use of buildings).