I recently saw a reference made to a R-4 residential group, which left me confused, as I knew only three occupancy classification for residential group. So what is R-4 Occupancy group?
NYC building code 2014 has R-1, R-2 & R-3 occupancy classifications for the residential group. International building code 2018 has new classification as R-4. It is defined as space for 5 or more but less than 16 persons, who are supervised in residential environment and receive custodial care. This occupancy includes, alcohol and drug center, assisted living facility, congregate care facility, group homes, halfway homes.
ArchitectNYC 