About our research project

Energy refurbishment and modernization of the housing stock play a key role in municipal climate protection concepts. However, their practical realization encounters large problems. The diversity and motivations of homeowners and tenants, especially elderly people or people with migration background and those confronted with increasingly dynamic real estate markets in growing or shrinking regions have hardly been addressed. Therefore, the connected challenges remain unanswered and opportunities unseen. In the light of the above, a toolbox for municipalities with target group oriented measures, instruments and strategies will be developed, based on the analysis of specific cases in several case municipalities. The toolbox is designed to also take into account the various living situations of owners and tenants. With the aid of a residential building and household model, the gained insights will be up-scaled to the German national level in order to better design instruments for energy efficiency policy in the building stock integrating instruments of environmental, social and housing policy in a sustainability perspective.

The project is funded by German Federal Ministry of Education and Research (BMBF).

Overview of the research project

The energey retrofit of residential buildings is going on slowly. One reason for this situation is the inadequate consideration of the instruments, the variety and motivation of the people making the decision of a retrofitting action. The variety concerns for example the actual or future real (or felt) financial situation, the personnel perspective of living, the status of information as well as the perspective of the building, which is deviated from the location, living environment and constructional condition.


Especially the demographic dynamics, which vary on a small scale, are hardly considered. This leads to a negligence of the diversity of the society and the corresponding challenges and chances. The prizes of real estates in growing areas is already high enough, that the assets for a basic energetic retrofit is not available after buying a real estate. Retrofitting is as well not very attractive from the view of a landlord, because the costs of retrofitting can hardly be apportioned due to already stongly increasing rents and high additional charges are accepted. The unknown development in decreasing areas can lead to barrier to retrofitting, even though it can be worth retrofitting, especially in better locations of these areas, in order to reduce the risk of vacancy.


The increasing share of elderly people has as well implications for retrofitting, because they generally earn little money as employees and the best time for retrofitting will have passed in the future. But there are synergies like barrier-free buildings to exploit.

The enterprise depends on the assumption, that the municipal level is the best level for the implementation due to the close contact to the actors and the interdependences of the challenges with municipal politics like noise prevention, quarter management and urban development promotion program, but needs supporting instruments on the national level.


The overall aim is the improvement of existing instrument of environment-, social- and housing market-policy towards effective retrofitting campaign of residential buildings. The pursued campaign is defined as a process, which includes the interests and acting opportunities of different actors for the energetic retrofit of residential buildings and creates a framework, which makes it possible for many actors to retrofit the varying stock of residential building in Germany together. Therefore, the project is not limited to a technical level of residential buildings but includes provision beneficiary, especially their motivation and room for maneuver, as well as other actors. The main addressee of the program are the municipalities.


Sub-ordinate targets include:

  • The development of a tool-box with target group orientated actions, instruments and strategies on communal level for sustainable energetic retrofitting of residential buildings and
  • The upscale of the results on national level to develop the most effective and most efficient instruments, which are coordinated with the local level.

What is planned?

The project pursues an integrated approach with case studies with transdisciplinary character and aggregated models, which combine the following elements:

  • an empirical established analysis of the living situation of the actors and their norms and motifs,
  • analysis of the technical and economical retrofitting potential of residential buildings,
  • analysis of the local framework (demographic development, migration and interdependencies with real estate industry, funding of house building, handcraft, etc.),
  • a residential-building-household-model to upscale the results on national level.

Cooperating municipalities for the realization of case studies are the cities Baunatal (HE), Dortmund (NRW), Garching (BY), Hamm (NRW), Hauzenberg (BY), Homberg (Efze) (HE). Following the transdisciplinary character of the project the partner municipalities are included in the research process and help to design it according to their potential.

How is the project arranged?

The project is parted in 8 working packages:

  • WP1 Situation of the practical municipalities
  • WP2 Scenario of communal development
  • WP3 Selection of specific cases in the practical municipalities
  • WP4 Work on the cases in the practical municipalities
  • WP5 Reflecting of the analyzed cases with view on instruments
  • WP6 Implementation in the residential-building-household-model
  • WP7 Deviation of recommendations and distribution
  • WP8 project management