"The ambition of SB 50 is to turn the clock back to an earlier era—not just pre-1970, but before the Great Depression, when single-family homes in growing cities were commonly torn down and replaced by small apartment buildings. After World War II, this pattern of incremental densification largely disappeared. Today, the expansion of urban housing stock is basically confined to formerly industrial and commercial zones. The majority of buildable land in major cities remains locked up in the zoning straightjacket. Once a tract has been zoned and developed for single-family homes, it’s stuck."