501.9 Open, accessible attics.

When performing additions, alterations, or repairs in Group 3 R occupancies of six units or more under a building permit with a cost of construction of $50,000 or more, fire blocks, draftstops, or fire safing insulation (approved noncombustible material used as a fire barrier) shall be installed in open attics of 30 inches in height or greater that are accessible from other than an occupied residential unit.

E xception. This requirement shall not apply to mandatory seismic strengthening alterations being performed pursuant to Chapter 5E of this Code.