: A block of three buildings in Lyon Confluence Hikari is a mixed-use complex located in Lyon (Confluence district), designed by Kengo Kuma between 2012 and 2015. Covering approximately 12,800 m² across three interconnected buildings, it brings together housing, offices, and retail spaces. It is recognized as the first positive energy urban block in Europe, meaning it produces more energy than it consumes for electricity, heating, and cooling. The buildings are designed to act as active energy producers. Climate-friendly energy The project relies on a combination of climate-friendly energy systems. Photovoltaic panels are installed on the roofs and façades, while solar glass façades generate electricity and regulate daylight. Energy production is further supported by combined heat and power systems using rapeseed oil, geothermal energy, and cooling drawn from the Saône River. This hybrid approach integrates multiple renewable sources. Energy efficiency through passive design Energy efficiency is also achieved [...]