Since February 2017 all houses built by Chiemgauer Holzhaus are allowed to bear the RAL quality mark GZ 425. This means that due to the material properties in the production process, the wooden houses store larger amounts of CO2 than are required during the production process.

The “Co-ordination of CO2 neutral buildings in wood e.V.” tests and monitors the energy balance of buildings whose energy balance during the manufacturing process has a GWP (Global Warming Potential) of less than zero. This means that a structure must have been produced at least CO2-neutral, or even a CO2-sinking performance.

Taking into account all necessary materials, such as concrete foundations, roof tiles, glass windows, etc., this means a CO2 sinking capacity of approx. 23,000 kg in the case of a massive wooden house with approx. 150 m² of living space.

For comparison, a conventionally built house with brickwork and otherwise equal conditions puts the environment at risk with 24,000 kg of CO2.