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2009 IBC Hole in Floor Calculator

Jonathan Ochshorn

contact | academic homepage | ARCH 2602/5602 homepage | calculator homepage | 2012 IBC Hole in Floor Calculator

Directions: Enter values for number of floors connected, occupancy, whether hole is an "atrium," whether hole is part of means of egress or contains a non-egress stair or escalator, whether the building is sprinklered, and whether the hole is open to certain types of corridors. This calculator then tells you if your proposed hole is permitted (per 2009 International Building Code). Aside from covered mall buildings (which have their own rules, per IBC Sec. 402), there are five main permitted hole categories:

  1. Atrium
  2. Hole connects only 2 floors and is not part of a means of egress
  3. Hole connects only 2 floors and is part of means of egress (i.e., hole contains egress stair)
  4. Hole contains non-egress stair/escalator
  5. Within dwelling units (Group R), holes connecting no more than 4 floors are permitted. Within housing units (Group I-3), holes are permitted if four criteria are met.

For additional information and limitations for these categories, read this more detailed discussion of holes in relation to the 2009 International Building Code (IBC). I also have a slightly different calculator based on the 2012 IBC. Figure 1 (below) illustrates a possible hole in a building floor.

Press "update" button.

How many floors are being connected by the hole?
Is hole defined as an atrium?
Is hole part of a means of egress?

sketch showing hole in building floor
Fig. 1. Sectional perspective showing hole in building floor, admittedly exaggerated.