The calculation of the energy performance and production has been made according to national standards.

Our future homes need to provide healthier, more comfortable living environments – without negatively impacting our climate. LichtAktiv Haus offers a high standard of living full of fresh air and daylight while covering its entire energy demand, including electricity, through renewable energy.
 
This is a particular challenge when renovating older homes as they often have much higher energy demands. 
 
Roof windows
Despite its lack of a heat recovery system or central air conditioning, which are often too costly to implement in older homes, LichtAktiv Haus is able to achieve carbon-neutrality. The home’s automated roof windows make a remarkable contribution to this by providing natural ventilation. An efficient control system automatically opens and closes the windows according to the temperature, CO2 concentration and humidity in order to create a healthy indoor climate.

Click here to see how LichtAktiv Haus' energy performance compares to the other Model Home 2020 experiments.

During the winter, passive solar heat gain through the roof windows reduces the need for heating, while shutters and blinds help prevent overheating in the summer. The windows combine optimum solar gain transmittance (g-value) and thermal transmittance (U-value), and they face the sun in order to reduce the use of artificial light. 

Solar energy
An air-water-heat pump and 22.5 m² of solar collectors work together to supply the home with heating and hot water. This highly-efficient technology reduces greenhouse gas emissions by minimising the need for conventional energy. The home’s 75 m² of polycrystalline photovoltaic cells on the roof power the heat pump and also act as a source of environmentally friendly electricity.
Sun protection and rain collection
The many windows in LichtAktiv Haus have shutters and blinds to ensure a comfortable indoor climate at all times. During the summer, south-facing shutters shield the house from the sun in the afternoon. And on the building’s western side, external awning blinds lower automatically in the afternoon. In the evening, the shutters and blinds are raised again to let in the fresh, cool air. In the colder months, the shutters stay up to allow passive solar heat to warm the home, and at dusk the shutters close to keep the heat inside.

Along with water-saving fixtures throughout the house, LichtAktiv Haus also features water collectors that supply rain water for the washing machine, garden watering and toilets.