The Sprinklered Corridor Interpretation
A developer submits plans for a 4-storey, 92-foot-tall Group R-2 apartment building of Type III-B construction. The design uses a single exit stairway serving all floors, with an open corridor system and no sprinkler system. The designer cites a code section allowing a single exit in buildings of limited height and area, and argues the corridor is 'open to the outside' and therefore qualifies as an exit access balcony. The plans examiner notes the building exceeds 75 feet in height, the corridor is enclosed on three sides with fixed glazing, and the occupant load per floor is 38. The designer responds that the glazing is openable and the building is 'effectively' an open-corridor building.
1. How should the examiner evaluate the single-exit and open-corridor arguments?
Read the worked answer
The examiner should separate the two claims. First, single-exit allowances in residential occupancies are conditioned on height, sprinkler protection, and exit-access configuration; a 92-foot building exceeds typical low-rise thresholds, and the absence of sprinklers removes the trade-off that usually justifies a single exit. Second, 'open corridor' status is not a matter of opinion - it requires the corridor to be open to the exterior atmosphere along its length, with limited enclosure. Fixed glazing on three sides, even if some panels open, does not convert an enclosed corridor into an exit-access balcony. The examiner's reasoning should be: identify the applicable occupancy/height/construction limits, test each condition of the allowance independently, and reject the 'effectively open' argument because the code tests physical configuration, not designer intent. The correct outcome is a plan-review comment requiring either a second exit or sprinkler protection plus a compliant exit-access arrangement.
2. The designer asks for an informal meeting to 'work out' an equivalent solution. What is the proper process, and what should the examiner avoid?
Read the worked answer
The examiner may explain the code basis and suggest compliant alternatives, but must not negotiate an equivalency informally. Equivalencies and alternative methods require a documented submission with technical justification, and typically approval by the building official after review - often with fire-service input. The examiner should avoid: (a) verbally blessing a design that will later be built, (b) accepting a designer's assertion of performance without calculations or test data, and (c) creating a record that suggests the department approved a noncompliant configuration. The proper path is a written request for an alternate-means-and-methods determination, with the examiner's analysis attached. If the request is denied, the designer's remedy is the formal appeal process, not a side conversation.