A comprehensive and detailed Guidebook (Meyer et al., 2023) was prepared to provide target group-oriented recommendations for policymakers and investors/decision-makers. As a supplement to this Guidebook, two complementary versions offer more straightforward guidelines oriented to each target audience, with a summary of the main recommendations. This document provides guidance for investors and decision-makers only.@en

A comprehensive and detailed Guidebook was prepared to provide target group-oriented recommendations for policymakers and investors/decision-makers. As a supplement to this Guidebook, two complementary versions offer more straightforward guidelines oriented to each target audience, with a summary of the main recommendations. This document provides guidance for policymakers only.@en

The guidebook illustrates that the district, as an action level for building renovation, allows for synergies through combinations of energy efficiency measures and measures that promote the use of renewable energy and opportunities for stakeholders to cooperate, compared to an individual building approach. But building renovation at the district level also presents challenges. These include high upfront costs, a long payback time, and risks of not being implemented due to a potential withdrawal of some building owners at different stages. However, the studies also show that often the opportunities are greater than the challenges in district approaches, even if the cost-effectiveness of certain measures may not necessarily be one of these opportunities. One main conclusion from IEA EBC Annex 75 is that assessments must be carried out for each district renovation project since no "ready-made" or "one size fits all" solutions exist. Still, several techno-economic potentials for district solutions are apparent. Furthermore, the research indicates that the best renovation solutions for a district-level renovation depend on the district's starting situation. The building insulation level, the installed heating/cooling systems, the availability of renewable energy sources and the possibility of integrating renewable energy are determining factors.@en