The "Heidelberg Student Living" project showcases the energy efficiency and economic performance of an innovative form of the modular system for buildings with a timber structure, developed by LiWooD AG in Munich. The combination of an energy-efficient building envelope, air/water heat pumps and a high-performance PV installation reduces the costs for heating and hot water to practically nothing. The Schüco Alu Inside system windows, which are energy-saving windows to passive house standard with triple glazing and integrated window rebate ventilation, played a key role in the concept and design of the building envelope.