Section 810.1 Alterations Level 2, Lofts in existing buildings, of the International Existing Buildings Code adopted in this article, is hereby amended by the addition of the following sections:
Section 810.1 Scope.
The requirements of this section shall be limited to lofts in dwelling units in detached one- and two-family dwellings, townhouses, and Groups R-1, R-2, and R-3 occupancies that were originally constructed prior to the year 2020.
Section 810.2 Minimum Area and Dimensions.
Lofts shall have a floor area of not less than 35 square feet and shall not be less than 5 feet in any horizontal direction.
Section 810.2.1 Height Effect on Loft Area.
Portions of a loft with a sloped ceiling measuring less than 3 feet from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area of the loft. See figure 810.2.1.
Exception: Under gable roofs with a minimum slope of 6 units vertical to 12 units horizontal (50 percent slope), portions of a loft with a sloped ceiling measuring less than 16 inches from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the loft.
Section 810.3 Loft Access and Egress.
The access to and primary egress from lofts shall be of any type described in Sections 810.3.1 through 810.3.4.
Section 810.3.1 Stairways.
Stairways accessing lofts shall comply with the International Residential Code, as adopted, or with Sections 810.3.1.1 through 810.3.1.6.
Section 810.3.1.1 Width.
Stairways accessing a loft shall not be less than 17 inches in clear width at all points at or above the permitted handrail height. The width below the handrail shall not be less than 20 inches.
Section 810.3.1.2 Headroom.
The headroom in stairways accessing a loft shall not be less than 6 feet 2 inches (1,880 mm) as measured vertically from the sloped line connecting the tread nosings in the middle of the tread width.
Exception: The headroom for landing platforms shall not be less than 4 feet 6 inches.
Section 810.3.1.3 Treads and Risers.
Risers for stairs accessing a loft shall be a minimum of 7 inches and a maximum of 12 inches. Tread depth and riser height shall be calculated with the following formulas:
Tread depth = 20 inches (508 mm) minus 4/3 riser height
Riser height = 15 inches (381 mm) minus 3/4 tread depth
Section 810.3.1.4 Land Platforms.
The top tread and riser of stairways accessing lofts shall be constructed as a landing platform where the loft ceiling height is less than 6 feet 2 inches where the stairway meets the loft. The landing platform shall be 18 inches to 22 inches in depth measured from the nosing of the landing platform to the edge of the lost, and 16 to 18 inches in height measured from the landing platform to the loft floor.
Section 810.3.1.5 Handrails.
Handrails shall comply with the 2021 International Residential Code, Section R311.7.8.
Section 810.3.1.6 Stairway Guards.
Guards at open sides of stairways shall comply with the 2021 International Residential Code Section R312.1.
Section 810.3.2 Ladder Size, Capacity, and Incline.
Ladders accessing lofts are permitted. Ladders shall have 12 inches minimum rung width and 10 inches to 14 inch spacing between rungs. Ladders shall be capable of supporting a 300-pound load on any rung. Rung spacing shall be uniform within 3/8-inch. Ladders shall be installed at 70 to 80 degrees from horizontal.
Section 810.3.3 Alternating Tread Devices.
Alternating tread devices accessing lofts shall comply with the 2021 International Residential Code Sections R311.7.11.1 and R311.7.11.2. The clear width at and below the handrails shall be not less than 20 inches.
Section 810.3.4 Ships Ladders.
Ships ladders accessing lofts shall comply with the 2021 International Residential Code Sections R311.7.12.1 and R311.7.12.2. The clear width at and below the handrails shall be not less than 20 inches.
Section 810.3.5 Loft Guards.
Loft guards shall be located along the open side(s) of lofts located more than 30 inches (762 mm) above the main floor. Loft guards shall be not less than 36 inches (914 mm) in height or one-half the clear height to the ceiling, whichever is less. Loft guards shall comply with Section R312.1.3 of the International Residential Code, as adopted.
Section 810.4 Emergency Escape and Rescue Openings.
Lofts used as sleeping rooms shall meet the applicable requirements of the 2021 International Residential Code Section R310 and 2021 International Building Code Section 1031 for emergency escape and rescue openings.
Exception: Egress roof access windows in lofts used as sleeping rooms shall be deemed to meet the requirements of Sections R310 (IRC) and 1031 (IBC) where installed with the bottom of their opening no more than 44 inches (1118 mm) above the loft floor.