Socio-economic studies have been carried out in the course of the ''Landstuhl demonstration project'' with the aim of evaluating supporting and hampering factors for the realization of energy saving measures, especially for the use of innovation techniques and the use of passive solar energy in residential buildings. The results of two opinion polls have been presented by means of standardized personal interviews with building-owners (in the whole Federal Republic and in the demonstration area) and with building experts (264 persons questioned). The evaluations of the results of the opinion poll show that energy conservation plays an important but not a dominant part in the planning of residential buildings. In the ''Landstuhl area'' energy saving investments took an above-average high position (large impact of the demonstration project). The building-owners and experts most frequently wanted and recommended increased conventional measures. It could be shown that the imagination of the building-owners was asked too much when taking measures for the use of passive solar energy.