Sustainability Report

When compared to a newly constructed semi-detached house of the same size, built with bricks and traditional insulation, Haus Hoinka’s carbon emissions are reduced by 95 percent. The 140 cubic metres of wood used for the house also store around 100 tons of carbon.

Haus Hoinka was realised in massive ecological plywood construction. Exterior walls and covers are board plywood. The load-bearing structure is a cross-laminated timber construction, while the facade features floor-to-ceiling timber cladding. The interior surfaces are clad with clay building boards and plaster, as well as exposed wood. To protect the straw bales in the floor slab from moisture, the house was raised by one storey on a concrete cross and four columns.

Grain cultivation also helps to bind carbon — one hectare of wheat will absorb approximately nine tons of carbon dioxide. Building with straw reduces carbon emissions during construction and impacts positively on a building’s indoor climate. Straw insulation, a natural building material, does not require any chemical or synthetic additives.

Ennogie solar roof

A special feature of Haus Hoinka is the Ennogie solar roof, an active roof covering which supplies the building’s energy needs, including heating, cooling, lighting, domestic hot water, and electricity for various devices. The roof modules overlap, providing a tight thermal envelope and water-bearing layer. With the Ennogie solar roof, about 350 grams of harmful greenhouse gas are saved with every kilowatt hour of sustainably produced electricity.

Sustainability measures

• Ennogie solar roof supplies the building’s energy needs. 
• Straw bales combined with clay plaster form a thermal envelope for floors, ceilings, roof, and walls. 
• Raising the roof by an entire storey eliminates the need for complex waterproofing. 
• Adhesive joints are avoided whenever possible. 
• Heat pumps, battery storage, and the option of a wall box for electric vehicles are also available.

Data via Ennogie for Haus Hoinka

• Electricity production: 23,355 kWh/p.a.
• Roof surface: 345 square metres
• Performance: 29.4 kWp

Haus Hoinka meets both the KfW Efficiency House 40 Plus standard and the Efficiency House Plus standard, as it achieves a negative annual primary energy demand and a negative annual total energy demand. To meet these standards, the building includes renewable energy sources, high levels of insulation, efficient heating systems, and controlled ventilation. It generates more energy on-site than it consumes, and utilises advanced building technologies.

Heating is provided by a heat pump, which supplies the ceiling heating from activated clay building boards.