Day Care Conversion in a 1925 Building: Alteration Level, Change of Occupancy, and a Stamped Plan
A 1925 two-story building of 9,000 sq ft per floor, with brick bearing walls and wood floor framing, has operated as an office for decades and has no automatic sprinkler system. A tenant holds a permit to convert the entire second floor into a child day care for 50 children and 8 staff, served by a 1920s open stair that rises from the first-floor lobby, with 36 in corridors and no second stair on that floor. The architect's narrative invokes the existing building code's Level 2 alteration classification, reasoning that the work area is 100 percent of the second floor but under 50 percent of the building's total floor area, and adds that the plans examiner already stamped the drawings. Demolition is complete, framing of new partitions has begun, and the contractor wants a framing inspection this week before the "exit stair question" is sorted out.
1. Classify the work under the existing building code and explain whether the change of occupancy drives additional requirements.
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Two separate determinations are being conflated, and the architect's reasoning is only half right.
Alteration level: under the work area compliance method, the level is set by the work area as a percentage of the aggregate area of the building, not of the story. Here 9,000 of 18,000 sq ft is 50 percent, which sits exactly on the boundary between Level 2 and Level 3. Whether the threshold is "more than 50 percent" or "not less than 50 percent" must be read in the edition in force, and the calculation must be confirmed rather than accepted from the narrative.
Change of occupancy: this is the controlling issue. A change from business to educational occupancy is governed by the change-of-occupancy chapter regardless of the alteration level. The building must satisfy the requirements for the new occupancy, including means of egress, fire separation, and any automatic sprinkler threshold tied to fire area or height, with whatever allowances the code gives for the existing structural system. The architect's alteration level does not insulate the project from that chapter, and the plan approval does not either.
2. Evaluate the egress provisions for 50 children and 8 staff: exit count, corridor width, and the open stair.
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Occupant load: 50 children plus 8 staff gives a design load of 58, which exceeds the 49-occupant threshold at which two exits become mandatory for this occupancy. One stair is therefore insufficient, and the second exit must be remote from the first to the degree the code demands, not a second door onto the same landing.
Corridor width: capacity requires only about 12 in at 0.2 in per occupant, so the table minimum governs. Corridors serving an occupant load of 50 or more must be 44 in wide, so the existing 36 in corridor fails, and that failure extends beyond the new suite because it lies on the path of egress.
Open stair: an educational occupancy above the first story requires a rated enclosure for the stair, and a 1920s open stair from the lobby provides no separation and no protected path. It must be enclosed, or the building sprinklered where the code permits the omission, and the travel distance from the far corner must be measured against the limit for the new occupancy.
These are not finish items that can be deferred; they determine whether the space may be occupied at all.
3. The contractor says the plans were already stamped and asks to proceed. How do you handle the discrepancy and the inspection request?
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The stamp is an administrative fact, not a code defense. An approved plan that conflicts with the code does not become compliant, and an inspector who signs off because someone else approved it inherits the liability.
Process matters, though. The field inspector should not unilaterally reverse a plan review decision in the driveway. Route the discrepancy to the building official in writing the same day: the occupant load, the exit count, the corridor width, and the stair enclosure, with the code basis and the edition. Ask for revised plans or a written determination.
On the framing request, split it. New partitions that do not affect egress, structure, or fire separation can be framed and inspected, with a written note limiting the inspection to that scope. Anything touching the stair, corridor, or exit access stays on hold.
Document the sequence: what you observed, what you told whom, and when. Advise the owner of the code modification and board of appeals routes, and make clear that no certificate of occupancy will issue for an educational occupancy without a compliant second exit.