ENERGY+ BUILDING CONCEPT – LISI is a plus-energy home generating all its required energy with a roof-mounted PV array. The supply of cold and hot water for space heating, cooling and for domestic hot water relies on two air-water heat pumps. Comfortable air conditions are provided by an ERV unit, which acts as a heat and humidity exchanger between used exhausted air and fresh intake air. A functional floor system regulates the entire buildings climate using water, air, and active cubic capacity. It efficiently provides heating, cooling, and fresh air to create a consistently comfortable indoor climate. An innovative shower tray recovers thermal energy from drain water through a heat exchanger, significantly reducing the net energy consumption needed for daily hygiene.