EXCEPTIONS: | 1. A cumulative increase in the occupant load of less than 50 for occupancy categories A or I. |
| 2. A cumulative increase in the occupant load of less than 25 for E occupancies. |
| 3. R-3 occupancies, and all other R occupancies with an increase of 5 dwelling or sleeping units or less. |
| 4. A cumulative increase in occupant load of less than 100 for occupancy categories M or B. |
| 5. A cumulative increase in the occupant load of less than 10 for H occupancies or S occupancies using hazardous materials. |
503.19.1 Large buildings. Buildings four or more stories or buildings more than 12,000 square feet shall be required to perform seismic evaluation in accordance with Section 304.3. Any lateral resisting elements shall be required to comply with design requirements for reduced seismic forces in accordance with Section 304.3.2 where found to be deficient.
503.19.2 Parapet bracing. Buildings with parapets constructed of unreinforced masonry where the parapet height to thickness ratio exceeds 1.5:1 shall be required to have parapets anchored, removed, or altered to resist out-of-plane seismic forces unless an evaluation demonstrates compliance of such items. Use of reduced seismic forces in accordance with Section 304.3.2 shall be permitted.
503.19.3 Floor and roof wall anchors. The alteration work shall include the installation of wall anchors at the floor and roof lines unless an evaluation demonstrates compliance of existing wall anchorage. Use of reduced seismic forces in accordance with Section 304.3.2 shall be permitted.
503.19.4 Bracing of partitions and nonstructural walls. Unreinforced masonry partitions and nonstructural walls within the alteration area and adjacent to egress paths from the alteration area shall be anchored, removed, or altered to resist out-of-plane seismic forces unless an evaluation demonstrates compliance of such items. Use of reduced seismic forces in accordance with Section 304.3.2 shall be permitted.
[Statutory Authority: RCW
19.27.031 and
19.27.074. WSR 23-23-102, § 51-50-480503, filed 11/15/23, effective 3/16/24. Statutory Authority: RCW
19.27.031,
19.27.074, and
19.27.540. WSR 23-02-073, 23-12-103, and 23-20-023, § 51-50-480503, filed 1/4/23, 6/7/23, and 9/25/23, effective 3/15/24.]