A support apparatus for a construction safety net. A frame is configured with a length sufficient to span at least two floors of a building under construction, and a width defined by parallel vertical support posts. Pairs of mounting brackets are affixed at or near the edges of adjacent exposed floors of the building. Each mounting bracket has a channel portion extending beyond the edge of the respective floor and aligned with the channel portions of mounting brackets affixed on adjacent floors. The vertical support posts of the frame are movable through the vertical channels and can be lifted up into the next pair of channel portions as additional floors are built out. A locking mechanism is used to secure the vertical support posts to the brackets.