An innovative timber construction pushes the boundaries of sustainable building. The Openly Valley apartment building in Widnau consists of 19 apartments and combines pioneering technologies with traditional building materials. The core of the building in the basement and the staircase were built using plant-based charcoal concrete developed in-house. Particularly noteworthy is the use of 400 cubic meters of hempcrete and 2,600 square meters of hemp bricks, which makes the building the largest "hemp house" in Europe. The innovative choice of materials results in CO2 savings of around 900 tons compared to conventional construction methods.

The building physics are optimized by 400,000 kilograms of loam fill in the ceilings and 48,000 kilograms of loam building boards in the apartment partition walls. This massive storage mass supports the passivity of the timber construction. The wet rooms were prefabricated with dade design and have a Joulia heat recovery system.

A digital control system, OPENLY OS, coordinates all home automation and energy management. Integrated storage tanks with battery and water systems as well as controlled decentralized living space ventilation using OPENLY airboxes (ventilation wings) enable particularly efficient operation. The high quality has been confirmed by Minergie-P certification and funding

The passive energy stored in the house makes it possible to massively reduce the heating and cooling energy requirements so that the yield from the photovoltaic system makes the OPENLY a plus-energy apartment building.