CEO/IBK consulting engineers for building technology, smarthome renewable and sustainbale energies, since 1970. Building technology (heating, ventilation, sanitary and electrical engineering, biomass local and district heating supply, renewable energy systems as well as solar power. Total number of projects completed > 1.600, up to 50 annually https://www.linkedin.com/in/jürgen-köberlein-7b88b1116/