The core activity of HGU (Hartmann Gesunde Umwelt GmbH) is consulting and planning energy-efficient and healthy buildings. This includes in particular: energy consulting and planning for building modernizations and new constructions, conception and implementation of energetic renovations and modernizations, planning and execution of building technology projects (heating, ventilation, air conditioning, cooling, sanitation, electrical), creation of energy certificates and building energy certificates, construction supervision and analysis (building physics, fire protection, indoor climate), and expert opinions for building damage and pollutants. The company offers its services primarily to private and public building owners, tenants, teachers, students, authorities, and property managers.