ReBuildStock - Portfolio management for the decarbonisation of larger housing stocks

Starting point / motiviation

The building sector, which accounts for 40% of final energy consumption and 36% of greenhouse gas emissions across the EU, has a crucial role to play in achieving climate targets. About three quarters of the stock is not energy efficient and will require ambitious energy retrofits and decarbonisation over the next 20 years, if the Austrian government's goal of climate neutrality in 2040 is to be achieved. Decarbonizing this huge housing stock is a Herculean task for housing developers.

Contents and goals

The goal of the ReBuildStock project is to develop a method and tool to support the decision-making processes of owners of larger housing stocks in developing strategies for the rapid and socially responsible decarbonisation of their building stock. The method and tool are used to answer the following questions:

• What is the current final energy consumption, what are the current greenhouse gas emissions of the total stock and the most important building types?
• For which properties is redensification sensible, for which is the option of demolition and replacement building advantageous?
• Which building types should be prioritised for refurbishment in view of energy/social policy objectives?
• Which options for heat supply exist - depending on the type of location - for the most important building types?
• Which renovation concepts will achieve the best possible energy and economic results (low warm rents) for the most important building types with the most efficient use of funds?
• How will the medium-term financial requirements develop?

Methods

The "RebuildStock Portfolio Method" is planned as a decision-making tool for automated selection of the timing and location of energy efficiency and refurbishment measures. The effect of these measures is verified by means of simulation and evaluated in terms of final energy savings and reduction of greenhouse gas emissions. Optimal combinations of measures for multi-storey residential buildings are determined in the overall context of the real estate portfolio, taking into account investment and life cycle costs.

ReBuildStock allows the simple alignment of the building stock with political, economic, ecological and social objectives. It proposes cost- and energy-efficient refurbishment measures fully automatically based on the current stock situation.

Expected results

• Development of a portfolio management method for the energy refurbishment of larger residential building stocks and for gradual decarbonisation
• Evaluation of the final energy demand and greenhouse gas emissions of the building stock of two housing developers by calculation compared with the actual energy consumptions
• Renovation measures catalogue for large building portfolios, models and simulations for the systematized evaluation of chronologically coordinated and comprehensive renovation roadmaps for individual buildings in the overall context of the real estate portfolio
• Support of real estate managers with large building portfolios in large-scale thermal refurbishments, heating conversions and building services modernizations with focus on life cycle costs, payback, CO2eq savings, maintenance costs, investment costs
• Derivation of recommendations for action for political decision-makers for the further development of funding programs on the basis of the findings obtained in the project

Project management

Energy Institut Vorarlberg

Project or cooperation partners

• AEE - Institute for Sustainable Technologies
• IIBW - Institute for Real Estate, Construction and Housing Ltd.

Energy Institut Vorarlberg
Thomas Roßkopf-Nachbaur
Campus V, Stadtstraße 33
A-6850 Dornbirn
Tel.: +43 (5572) 31202-58
E-Mail: thomas.rosskopf@energieinstitut.at
Web: www.energieinstitut.at