Buildings typically are expected to provide their inhabitants with the opportunity to influence the indoor environment using various control devices. These include, for example, windows, luminaires, radiators, and shading elements. The quality and adequacy of the indoor environment is thus dependent on the availability and effectiveness of such devices. There is arguably a lack of generally agreed-upon evaluation procedures for this aspect of buildings' indoor environment, namely its controllability by building users, or – in the terminology of Human Ecology – its "ecological valency". In this context, the present contribution explores the possibility to specify buildings' ecological valency in a systematic and reproducible manner. Toward this end, first the theoretical foundation for this purpose is identified and previous related efforts are briefly reviewed. Subsequently, a specific attempt for an ecological valency evaluation method is presented. As part of this approach, five main categories of control devices are documented in various rooms of a building. They include windows, shading, lights, heating and cooling systems. Whereas, the first component of this method deals with the basic availability of these control devices and elements, the second part looks at their spatial distribution, effectiveness (both objective and subjective), interface quality (to support user interaction), and ecological quality. The presented evaluation method is tested for six different rooms of an office area in an educational building in Vienna, Austria. Some thirty participants independently evaluated this area based on the proposed method and associated protocol. The results point to high degree of congruence between the evaluation results of different participants while judging the principle availability and typology of the control devices. Higher variation was observed in the evaluation of the quality of devices and their interfaces. As a whole, the results suggest that methods based on similar premises proposed in the present contribution may indeed provide a realistic opportunity to extend building performance evaluation procedures beyond energy and cost criteria to cover aspects pertaining to user control and satisfaction.