Regarding mass timber in a seismic area - http://nheri.ucsd.edu/projects/2017-development-validation-seismic-design/ http://nheri.ucsd.edu/projects/2017-develop

Regarding mass timber in a seismic area - http://nheri.ucsd.edu/projects/2017-development-validation-seismic-design/ http://nheri.ucsd.edu/projects/2017-development-validation-s... and http://nheritallwood.mines.edu http://nheritallwood.mines.edu And the beam size gets into "don't design a concrete building and swap in mass timber". https://www.woodworks.org/resources/creating-efficient-structural-grids-in-mass-timber-buildings/ https://www.woodworks.org/resources/creating-efficient-struc... Another aspect to the beams is that the structural elements are often left bare for aesthetics ( https://uploads.map-dynamics.com/0518_Structurlam-U.S.-Mass-Timber-Technical-Guide-April-2020.pdf https://uploads.map-dynamics.com/0518_Structurlam-U.S.-Mass-... ). Table 6 in https://www.structurlam.com/wp-content/uploads/2019/04/Structurlam-Design-Guide_FINAL_Spreads.pdf https://www.structurlam.com/wp-content/uploads/2019/04/Struc... gets into the snow loads and I don't know enough engineering to be able to do a comparison between mass timber and other building approaches. The main thing to consider is this isn't a "it costs 2x" or "it uses 2x more materials" because they are different materials with different designs. If comparisons are to be done, they should be done at the building level ("it cost X to make a N story building with M square feet per floor" and "building A had a sustainability rating of P while building B was rated at Q with a difference in cost of Z%").