Section 504.2/Allowable Building Height
IBC 504 establishes maximum building height in feet and stories based on occupancy and construction type.
The maximum allowable building height (in feet and number of stories) is determined by Table 504.3 and Table 504.4 based on the occupancy group and the construction type. Type IA construction allows the tallest buildings. Type VB allows the shortest. An automatic sprinkler system per 903.3.1.1 adds 20 feet to the allowable height and one additional story (with exceptions). Buildings with multiple occupancies must evaluate height limits for each occupancy and apply the most restrictive.
Why this section exists
Taller buildings present greater risks during fires: longer evacuation times, more difficult fire department access, and greater structural loads on the fire-resistance-rated assemblies. The height limits ensure that the building's construction type provides adequate fire resistance for the expected evacuation and firefighting timeline. Sprinkler systems earn height increases because they control fires early, extending the safe evacuation window.
What plan reviewers look for
Plan reviewers compare the proposed building height (in feet and stories, measured per Section 502) against the allowable values from Tables 504.3 and 504.4. They verify the construction type and occupancy used to look up the height limit. They check whether the sprinkler increase has been applied and whether the building qualifies for the increase.
Common violations
Related IBC requirements
Section 506 covers allowable building area (paired with height for the building size analysis). Section 602 defines the construction types and their fire-resistance requirements. Table 601 provides the fire-resistance ratings required for each construction type. Section 903.2 covers sprinkler requirements.