The structural development of buildings towards higher energy efficiency is a technically and economically challenging task. Therefore, it is necessary to check in advance which buildings are basically suitable for that purpose and which are not. The savings potentials vary, for example, according to the building typology, as e.g. the insulation of facades of prefabricated buildings (such as Plattenbauten) is usually significantly more effective and thus more economical than in masonry structures.
The decision for a comprehensive building renovation is also closely linked to the development of quantitative demand and the housing community structure. Furthermore, the nature of the local housing market has a noticeable influence on the yield development of the building stock, as do the urban development policy specifics.
The investment plan must also take into account that substantial rent increases are not enforceable in all local housing markets. Depending on the building type and age, the expected rent increase may be 1.5 to 4 times higher than the savings in heating costs.
The legal conditions can be found in EU directives and the depending national rules. Germany is in the lead with respect to the already achieved level of technical solutions for accomplishing the climate protection goals. The implementation of necessary constructions in the total national housing stock is not yet very advanced. Relevant laws are
The KfW Bank (major development bank in Germany) offers several funding programs that have been created specifically for the improvement of energy efficiency in existing or in newly constructed buildings. The key measure for the amount of funding are the KfW energy efficiency standards 55, 70, 85, 100 or 115 (measure of thermal heat demand, primary energy demand, and the transmission heat loss).
The federal states also support investments in energy efficiency by means of specific funding programs. In special cases, EU funds (ERDF) can be applied for.