A central component of the Building & Living project was the implementation of Group Delphi processes — designed both to validate and to complement the expertise of the working groups. The methodological design, implementation, and evaluation were conducted according to scientific standards by DIALOGIK – Non-Profit Institute for Communication and Cooperation Research.

The Group Delphi method represents a modification of the classical Delphi approach. Instead of relying solely on written surveys, the Group Delphi combines them with moderated workshops. By integrating discursive elements, it enables participants to substantiate their judgments and exchange reasoning in a structured dialogue. The method can thus lead to either consensual assessments or to a clear “consensus on dissent”, highlighting distinct positions.

Experts deepen the initial results of the working groups

Within the Building & Living project, two Group Delphi processes were conducted to integrate additional expert knowledge beyond the working groups. Participants were invited to discuss and assess the barriers identified by the groups, review the first proposed solutions, and contribute further perspectives and arguments.

The first Delphi took place in April at the acatech headquarter in Munich with the members of the platform’s stakeholder advisory board (12 participants).
The second Delphi was carried out in May and June as a specialist consultation with external experts through a series of three online workshops (5–9 participants each).

The discussions focused on five thematic areas:

• Planning of construction projects within existing buildings
• Neighbourhood development planning within existing structures
• Land activation and land policy
• Activation of stakeholders as well as residents within neighbourhoods
• Life cycle assessment of buildings and CO₂ emissions at the neighbourhood level

Key strategic insights and action points (excerpt):

• Facilitate building within existing structures as a key to transformation
• Integrate a Model Refurbishment Code into the existing Model Building Code
• Consider densification always in the context of building typology, social acceptance, and ecological factors
• Activate property owners through targeted incentive mechanisms
• Strengthen the link between land policy instruments and community-oriented goals
• Include embodied energy and durability of components in CO₂ assessments
• Promote resident participation and the development of social infrastructure

Read the full report (in German)