The Federal Office for Building and Regional Planning

Research Project: The investment processes of condominium owners' associations with particular emphasis on energy-efficiency and age-appropriate renovations

Project briefing

Condominium owners' associations too are concerned with investments in energy-efficiency and accessibility. It is clear they face formidable challenges here in terms of decision-making and the organisation of resolutions – even more so than they do with mere maintenance. They must work together and where possible unanimously decide which measures they want to implement, how they should be financed and who should plan and execute them. As part of the research project, the investment processes of condominium owners' associations were analysed with the aid of case studies.

Project duration: May 2012 – February 2015


When it comes to undertaking energy-efficiency and age-appropriate renovations, how do the consensus-building and decision-making processes of condominium owners' associations take place? The configurations are very diverse, the driving forces and inhibiting factors varied. As part of the research project completed in early 2015, the resultant willingness to invest was investigated and it was demonstrated which considerations contribute to positive and negative results. Following this, courses of action are then set out which can more easily facilitate the energy-efficiency and age-appropriate renovation of condominium owners' association properties.

There are nearly 9 million condominium apartments in Germany, according to the 2011 census, which is roughly 22 percent of the total housing stock. Given that for some time now a high proportion of condominiums are new-builds and the discernible trend of rental apartment blocks being turned into owners' association condominiums continues (particularly important for current portfolio investments), further future increases in the proportion of condominiums are to be expected.

The energy-efficiency and age-appropriate renovation of residential buildings are important, but complex and often costly construction projects. In order to preserve the value of the housing stock and for the quality of life of residents, but also to meet climate objectives, it is important that the existing potentials of these stocks are exploited and that condominium owners' associations invest in energy-saving measures and age-appropriate modernisation. The planning and implementation of such renovations is already a challenge for most individual owners. But condominium owners' associations are faced with numerous additional hurdles: the owners involved often have different interests and financial capabilities. The legal relationships are complicated and – depending on the type of renovation measures involved – place high demands in terms of preparation and majorities during decision-making.


With a focus on energy-efficiency and age-appropriate renovations, the purpose of the research project was to analyse the consensus-building and decision-making processes of condominium owners' associations in different constellations (for energy-efficiency and age-appropriate remedial measures) and to evaluate the resultant willingness to invest and any possible obstacles. For this purpose, suitable examples have been selected and analyzed in the form of case studies. It should be deduced from the results:

  • what the typical structures and features of both successfully implemented and failed condominium owners' association renovation projects are,
  • what obstacles are present and what options are available to facilitate and accelerate investment in energy-efficiency and age-appropriate condominium owners' association renovations against this backdrop,
  • how important managers and administrators are in these internal investment processes and how they fulfill their roles,
  • how financing and funding opportunities can promote condominium owners' association investment.

The contractors of the research project were:

  • Weeber+Partner Institut für Stadtplanung und Sozialforschung, Stuttgart/Berlin
  • G.A.S. planen bauen forschen, Stuttgart

in cooperation with
ECONSULT Lambrecht Jungmann Partnerschaft, Rottenburg,
Rechtsanwälte Dr. Greiner und Kollegen, Tübingen.


  • Christoph Zander
    Division WB 13 "Housing and Property Industry, Construction Industry"
    Phone: +49 228 99401-1585

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