Here in San Francisco, CLT won't be legal for buildings over six floors until about 2023 because of dumb policies. California uses the International Building Code as its base building code and then modifies it based on particular laws we have here. This modification & ratification process takes about two years. Then San Francisco does the same thing, adding another two to three years (because surely _our_ engineers are better than a consortium of the world's best structural engineers...)<p>The 2018 International Building Code provides codes for tall CLT structures, which won't get adopted in the CA code until late 2020, which won't get adopted in the SF code until late 2022 or 2023. At that point, developers can start applying for permits for CLT buildings, which takes about four to five years. Then add two years of construction.<p>So SF won't see CLT structures over six floors until about 2030. Makes you realize how unseriously we're taking climate change when the only carbon-negative structural building material in existence won't exist here for another decade.