Exercise of all activities in the field of building services and building technology, in particular planning, construction, service and operation of heating, air conditioning, ventilation, sanitary and refrigeration systems as well as electrical installations, furthermore technical operation management and monitoring of energy centers and plants of all kinds; may establish branches and subsidiaries, participate in other companies, acquire, encumber, sell and manage real estate, arrange financing for its own or third-party account, and provide guarantees and sureties for subsidiaries and third parties.