Spatial Separation

Maximum unprotected opening area in an exposing building face, based on limiting distance, face area, and occupancy.

Exposing Building Face

Width

Height

Limiting Distance

From the exposing face to the property line (or imaginary line between buildings on the same property)

Major Occupancy

Group A, C, D or F Div 3Assembly, residential, office, low-hazard storage

Group B (Care or Detention)Hospitals, nursing homes, detention — sprinkler system recommended

Group E or F Div 1 / 2Mercantile, medium or high hazard industrial

Building is sprinklered throughout

Based on OBC Article 3.2.3.1 and Tables 3.2.3.1.-A through -E. Same values in 2024 and 2012 editions. Limiting distance measured perpendicular to the exposing building face per Article 3.2.3.1.(1). Results are a starting point — verify against the specific edition applicable to your project.