NFPA 101-7.1.3.1 - if corridor is used as "Exit Access" and will serve >30 occupants, then it's walls must be 1-hour fire rated. Though this shall not apply where otherwise requirements are provided in table below.
OCCUPANCY TYPE (new building) CODE REF. CORRIDOR WALL FIRE RATING REQUIREMENTS
AMBULATORY (Not Sprinklered) (20.3.6.1 and 38.3.6.1) 1-hour, No Requirement if occupied by single tenant,
AMBULATORY (Sprinklered) (20.3.6.1 and 38.3.6.1) No Requirement
ASSEMBLY (Not Sprinklered) (12.3.6.1) 1-hour if OL > 30, No requirement if 50% of exit capacity is discharging to outside.
ASSEMBLY (either Sprinklered or with smoke detection system) (12.3.6.2) No Requirement
BUSINESS (Not Sprinklered) (38.3.6.1) 1-hour, No Requirement if occupied by single tenant,
BUSINESS (Sprinklered) (38.3.6.1) No Requirement
HEALTHCARE (18.3.6.1) Limit transfer of smoke
EDUCATIONAL (Not Sprinklered) (14.3.6) 1-hour,
EDUCATIONAL (Sprinklered) (14.3.6) Wall to be smoke partition
ONE & TWO FAMILY DWELLINGS (-) No Requirement
HOTELS AND DORMITORIES (Not Sprinklered) (28.3.6) 1-hour
HOTELS AND DORMITORIES (Sprinklered) (28.3.6) 30-minutes
APARTMENTS (Not Sprinklered) (30.3.6.1) 1-hour
APARTMENTS (Sprinklered) (30.3.6.1) 30-minutes
MERCANTILE (Not Sprinklered) (36.3.6.1) 1-hour, Not Required if space is occupied by single tenant
MERCANTILE (Sprinklered) (36.3.6.1) No Requirement
STORAGE (42.3.6) No Requirement, provision of 7.1.3.1 shall not apply
Notes: