Second-Floor Dance Studio Change of Occupancy
A tenant improvement permit proposes converting a 2,400 ft² second-floor suite in a two-story Type V-B building from business offices to a dance studio. The building has one interior exit stair 44 inches wide serving both floors; the first floor contains 3,000 ft² of mercantile. The suite has a single 36-inch door to the stair, no automatic sprinkler system, and a manual fire alarm with pull stations and horns. The owner calculates occupant load at 118 using 20 ft² per person for the dance floor. The stair discharges through a 6-foot corridor past the mercantile checkout. There is no fire escape. The owner wants to open in 30 days. You are reviewing the change of occupancy and egress. The suite has 12-foot ceilings and windows with 5-foot sill height.
1. What occupancy classification and occupant-load issues must you resolve before accepting the owner's 118-person calculation?
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Start by separating occupancy classification from the owner's arithmetic. A dance studio with an occupant load over 49 is an assembly occupancy, likely A-3 unless food or drink service makes it A-2. The 20 ft² per person factor is not a default for assembly; use the actual function areas and the adopted code's factors, such as concentrated assembly/dance floor versus unconcentrated areas. If the dance floor is 900 ft² and the remaining 1,500 ft² is lobby/support at 15 ft² per person, the load may exceed 118. Because the calculated load exceeds 49, two means of egress are required. A single 36-inch door and one interior stair cannot satisfy that, even if the stair width is numerically adequate for 118 (44 in divided by 0.3 in per occupant equals about 146 unsprinklered). Also check common path, travel distance, door swing, panic hardware, exit signage, and emergency lighting. Do not accept the posted load as a substitute for calculated load.
2. The owner proposes to keep the single stair and reduce the posted occupant load to 49. Evaluate whether that resolves the egress problem and identify remaining issues.
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Reducing the posted load to 49 does not by itself make the single stair legal. First, the calculated occupant load is based on use and floor area, not on a sign. Second, the stair serves the first-floor mercantile as well; if mercantile load is 3,000 divided by 30 equals 100 and the studio is 49, the combined load is 149, exceeding the stair's unsprinklered capacity of about 146. Third, assembly occupancies have door hardware and swing requirements. Fourth, the path through the mercantile checkout creates a common-path and hazard exposure issue. A code official could consider an approved alternative, but the inspector should require a design showing two remote exits, a protected stair, panic hardware, and adequate capacity. If the owner truly limits the studio to fewer than 50, confirm that the assembly classification threshold and all other egress requirements, including the first-floor mercantile, are still met.
3. Describe the inspection and approval path you would require.
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Require revised plans prepared by a registered design professional. The plans must show occupancy classification and occupant load by area; two remote exits with dimensions, door swings, and panic hardware; stair enclosure and discharge; travel distance and common path; fire alarm coverage; emergency lighting and exit signs; and any sprinkler requirement triggered by the assembly use. Review the change-of-occupancy provisions to determine whether existing elements must be upgraded to new-construction standards. During inspection verify door clear width, hardware, self-closing, stair headroom, handrails, exit sign illumination, alarm audibility, and that the discharge path does not pass through the mercantile in a hazardous way. Issue a correction notice for missing items and do not issue a certificate of occupancy until the second exit and alarm/egress items are complete and tested.