The combination building component is for the ingress of light and ventilation or air conditioning in a principal central upper story apartment. In combination and/or in the same vicinity are a hatch cover working together with a floor trap and at least one fresh air window-skylight and-or vertical air conditioning duct. At least one window and-or an air blower is suspended over the floor hatch cover-trap assembly. The window and blower can be spaced from the floor hatch relatively to the trap.
