IEA EBC Annex 75 – Cost-effective Building Renovation at District Level Combining Energy Efficiency & Renewables

Buildings are a major source of greenhouse gas emissions. The transformation of existing buildings to low-emission and low-energy buildings is a particular challenge in cities, where many buildings continue to rely to a large extent on heat supply by fossil fuels. At the same time, there are specific opportunities for district-level solutions in cities.

Within the context of reducing greenhouse gas emissions and energy use in buildings in cities, it is important to know which strategies are most cost-effective. In particular, it is of importance to find the balance between energy efficiency measures and renewable energy measures. Whereas this topic was examined at the level of individual buildings in IEA EBC Annex 56, there is a lack of research on this topic for groups of buildings. At district level, finding the balance between renewable energy measures and energy efficiency measures for the existing building stock is more complex than at the level of individual buildings.

This project aims to investigate cost-effective strategies for reducing greenhouse gas emissions and energy use in buildings in cities at district level, combining both energy efficiency measures and renewable energy measures. The objective is to provide guidance to policy makers, companies working in the field of the energy transition, as well as building owners for transforming cost-effectively the city’s energy use in the existing building stock towards low emission and low energy solutions.

Given the limitations due to available financial resources and the large amount of investments needed to transform the cities’ energy use in buildings, the identification of cost-effective strategies is important for accelerating the necessary transition towards low-emission and low-energy districts in cities.