HVAC specialist site management in the existing building on Giesshübelstrasse in Zurich. Dismantling of the ground floor and 4th floor with organization of the noisy work outside office hours. Individual stage preparations for  work between the floors which are in operation during the work. Coordination of the work with the tenants. Monitoring and checking safety regulations. Preparation and site management work for the construction of a roof monoblock with access to a new ventilation riser zone through the existing building.