As just one example, Most of the USA's building codes mandate double staircases in buildings over 3 stories for outdated fire concerns which increases cost per

As just one example, Most of the USA's building codes mandate double staircases in buildings over 3 stories for outdated fire concerns which increases cost per unit mainly by reducing the number of units that fit in a given site and the arrangement of those units. https://www.treehugger.com/single-stair-buildings-united-states-5197036 https://www.treehugger.com/single-stair-buildings-united-sta... https://twitter.com/holz_bau/status/1384670822351048707?ref_src=twsrc%5Etfw https://twitter.com/holz_bau/status/1384670822351048707?ref_...