Climate-Neutral Renovation Pathways For Multi-Unit Housing Portfolios, Taking Constraints Into Account

The housing sector is under pressure to find economically viable and socially acceptable ways to renovate its housing stock in a climate-neutral manner. Together with housing companies, “OptiPort” is developing a practical optimisation tool that calculates optimal renovation pathways for multi-family housing portfolios whilst accounting for real-world constraints such as skills shortages, financing and social acceptability. The project provides concrete renovation recommendations, assesses environmental and socio-economic impacts, and derives recommendations for action for the industry.

Initial Situation

The housing sector faces the challenge of renovating existing portfolios of multi-unit residential buildings in a manner that is swift, consistent with climate targets, economically viable and socially acceptable. To date, there has been a lack of systematic renovation pathways that take into account limited financial and human resources, skills shortages, corporate strategies, regional differences and social acceptability all at the same time. Decisions are often made in a fragmented manner and without a holistic assessment of costs, climate protection impact and social consequences. Optimised, practical and portfolio-wide strategies are therefore urgently needed for a successful heating transition.

Objective

“OptiPort” pursues the following objectives:

1. Development of a practical optimisation tool for creating climate-friendly, economically viable and implementable renovation roadmaps for multi-family housing portfolios.
2. Systematic assessment of the technical, environmental and (socio-)economic impacts of renovation pathways for housing companies and tenants.
3. Derivation of concrete recommendations for action to accelerate the heating transition.
4. Establishment of a sustainable, transferable approach for the entire housing sector.

Approach

As part of the OptiPort project, Fraunhofer ISE is working with research partners and housing companies to develop a tool for planning climate-neutral renovation pathways for portfolios of multi-family homes, based on mathematical optimisation. To this end, building data is collected, processed and fed into optimisation models that take into account technical measures, costs, CO₂ savings and social impacts. In workshops and other collaborative formats, practical requirements are integrated, conflicting objectives with stakeholders are analysed and scenarios are evaluated. This results in actionable renovation roadmaps as well as concrete recommendations for action for the housing sector.

Coordination of the collaborative project

• Institute for Ecological Economic Research (IÖW) GmbH

Collaborating partners

• Fraunhofer ISE
• Rheinisch-Westfälische Technische Hochschule Aachen – (RWTH Aachen)
• Albert Ludwig University of Freiburg

Associated partners

• Housing industry associations
  • Initiative Wohnen.2050, Association of the South-West German Housing Industry e.V.
• Housing organisations 
  • Nassauische Heimstätte Wohnungs- und Entwicklungsgesellschaft mbH
  • Volks- Bau- und Sparverein Frankfurt am Main eG
  • Heimatfriede Housing Cooperative eG
  • Bauverein für Höchst am Main und Umgebung eG
  • Housing Cooperative for Members of the Judiciary, Frankfurt am Main eG
  • Frankfurter Eisenbahnsiedlungsverein eG
  • Housing Cooperative in Frankfurt am Main eG

The “OptiPort” project is funded by the Federal Ministry of Economic Affairs and Energy (BMWE).