In spite of the large potential for solar collective systems within the German housing industry, up to now less than 2% (60 — 70.000 m2) of the total installed collector area in Germany are installed in large scale applications. In the view of housing companies the main barrier for implementation of solar collective systems is the difficult economic situation — with high investment costs for the installation and additional constraints caused by rent legislation (investor/user — dilemma).

German legislation allows to hand on the costs for solar thermal systems to the tenants. Nevertheless, considering the low economic efficiency of solar thermal systems, total costs are increasing which makes the dwellings less attractive for tenants.

Furthermore early installations of the last 25 years with wrong dimensioning and different malfunctions due to a lack of experience led to mistrust regarding quality and durability. Linked to this companies fear additional necessary work especially while often facing outsourcing tendencies of technical know-how within the housing industry nowadays. And while working closely together with preffered HVAC planning companies it is crucial that these planners are willing to integrate solar collective systems within a construction or refurbishment process.