Since 1990 Thoma has realized around 2000 buildings with building materials that have a positive impact on the inhabitant’s health and the environment. The pure wood construction system "Holz100" consists of wood and nothing else – it is free from additives like timber preservatives or glue. The building envelope has no moisture barrier or toxic outgassing and stores CO2. The walls even hold the world record in natural thermal insulation. Latest scientific research results have affirmed a lower rate of heartbeat and a strengthening of the immune- and the nervous system for people living in a pure wood environment. Holz100-houses are prefabricated in factories that are run by solar energy and produce no waste.