In some cases like here in Canada, many fire codes were written in the 30s and haven’t been significantly refactored since. For example, Canadian code says you

In some cases like here in Canada, many fire codes were written in the 30s and haven’t been significantly refactored since. For example, Canadian code says you need two stairwells for buildings with two or more floors. That substantially increases costs, reduces floor space, and encodes particular building design requirements. Think of how many building designs this inherently excludes (ie. single staircase brownstones.) Then realize that in 2024, we have sufficient technology where a second staircase perhaps isn’t the best first choice. Code and zoning is ripe for a rewrite. It would maybe the most significant change to affordability in our lifetimes.