The "Environment-friendly Energy Supply Systems and Energy-efficient Buildings" research cluster addresses the challenge of converting our energy supply network in response to the impact of climate change. Seeking to effect a drastic reduction in the energy demands of existing buildings, the project also investigates ways of converting to low-emission and renewable energy sources. The significance of indoor climates for human health, well-being and performance is another important area of research. A number of research projects in this cluster address systems for energy efficiency and environment-friendly construction. These projects seek to develop renewable heat supply strategies, improve thermal insulation and the sealing of building outer shells, and optimise systems engineering for heating, cooling and ventilation.