Design for CLT panels is from the CSA O86 Chapter 8 and Appendix A8. Guidance on reduced sections for fire design is from the FPInnovations CLT Handbook, 2013 Edition (referred to as CLT Handbook), Chapter 3, Structural and Chapter 8, Fire.
Note that the design methodology for standard CLT panels given in the APA PRG 320-19 Standard for Performance Rated CLT was derived from the Shear Analogy Method employed by both O86 and the CLT Handbook, and Sizer design yields the same results for these panels as the PRG 320 method.