When a change of occupancy classification is made to a higher hazard category (lower number) as shown in Table 1012.4, the means of egress shall comply with the requirements of Chapter 10 of the Florida Building Code, Building.
- Stairways shall be enclosed in compliance with the applicable provisions of Section 903.1.
- Existing stairways including handrails and guards complying with the requirements of Chapter 9 shall be permitted for continued use subject to approval of the code official.
- Any stairway replacing an existing stairway within a space where the pitch or slope cannot be reduced because of existing construction shall not be required to comply with the maximum riser height and minimum tread depth requirements.
- Existing corridor walls constructed on both sides of wood lath and plaster in good condition or 1/2-inch-thick (12.7 mm) gypsum wallboard shall be permitted. Such walls shall either terminate at the underside of a ceiling of equivalent construction or extend to the underside of the floor or roof next above.
- Existing corridor doorways, transoms and other corridor openings shall comply with the requirements in Sections 805.5.1, 805.5.2 and 805.5.3.
- Existing dead-end corridors shall comply with the requirements in Section 805.6.
- An existing operable window with clear opening area no less than 4 square feet (0.38 m2) and minimum opening height and width of 22 inches (559 mm) and 20 inches (508 mm), respectively, shall be accepted as an emergency escape and rescue opening.
When a change of occupancy classification is made to an equal or lesser hazard category (higher number) as shown in Table 1012.4, existing elements of the means of egress shall comply with the requirements of Section 905 for the new occupancy classification. Newly constructed or configured means of egress shall comply with the requirements of Chapter 10 of the Florida Building Code, Building.
In other than Groups H, F-1 and S-1, fire barriers and horizontal assemblies constructed in accordance with Sections 707 and 711, respectively, of the Florida Building Code, Building shall be permitted to be used in lieu of fire walls to subdivide the building into separate buildings for the purpose of complying with the area limitations required for the new occupancy where all of the following conditions are met:
- The buildings are protected throughout with an automatic sprinkler system in accordance with the Florida Fire Prevention Code.
- The maximum allowable area between fire barriers, horizontal assemblies, or any combination thereof shall not exceed the maximum allowable area determined in accordance with Chapter 5 of the Florida Building Code, Building without an increase allowed for an automatic sprinkler system in accordance with Section 506 of the Florida Building Code, Building.
- The fire-resistance rating of the fire barriers and horizontal assemblies shall not be less than that specified for fire walls in Table 706.4 of the Florida Building Code, Building.
When a change of occupancy classification is made to a higher hazard category as shown in Table 1012.5, fire barriers in separated mixed use buildings shall comply with the fire-resistance requirements of the Florida Building Code, Building.
When a change of occupancy classification is made to a higher hazard category as shown in Table 1012.6, exterior walls shall have fire resistance and exterior opening protectives as required by the Florida Building Code, Building.
1012.6.2 Exterior Wall Rating for Change of Occupancy Classification to an Equal or Lesser Hazard Category
Openings in exterior walls shall be protected as required by the Florida Building Code, Building. Where openings in the exterior walls are required to be protected because of their distance from the lot line, the sum of the area of such openings shall not exceed 50 percent of the total area of the wall in each story.
- Where the Florida Building Code, Building permits openings in excess of 50 percent.
- Protected openings shall not be required in buildings of Group R occupancy that do not exceed three stories in height and that are located not less than 3 feet (914 mm) from the lot line.
- Where exterior opening protectives are required, an automatic sprinkler system throughout may be substituted for opening protection.
- Exterior opening protectives are not required when the change of occupancy group is to an equal or lower hazard classification in accordance with Table 1012.6.
- In other than Group I occupancies, an enclosure shall not be required for openings serving only one adjacent floor and that are not connected with corridors or stairways serving other floors.
- Unenclosed existing stairways need not be enclosed in a continuous vertical shaft if each story is separated from other stories by 1-hour fire-resistance-rated construction or approved wired glass set in steel frames and all exit corridors are sprinklered. The openings between the corridor and the occupant space shall have at least one sprinkler head above the openings on the tenant side. The sprinkler system shall be permitted to be supplied from the domestic water-supply systems, provided the system is of adequate pressure, capacity, and sizing for the combined domestic and sprinkler requirements.
- Existing penetrations of stairway enclosures shall be accepted if they are protected in accordance with the Florida Building Code, Building.
Interior vertical shafts other than stairways, including but not limited to elevator hoistways and service and utility shafts, shall be enclosed as required by the Florida Building Code, Building when there is a change of use to a higher hazard category as specified in Table 1012.4.
- Existing 1-hour interior shaft enclosures shall be accepted where a higher rating is required.
- Vertical openings, other than stairways, in buildings of other than Group I occupancy and connecting less than six stories shall not be required to be enclosed if the entire building is provided with an approved automatic sprinkler system.