What happened: More than 4,220 units of housing began construction in San Francisco in 2012 — following a year in which just 269 net units were added.What it means: After years of underbuilding, new housing and commercial construction is booming in San Francisco.  Years of work on neighborhood plans and rezoning are paying off as new construction targets transit-served areas and neighborhoods that support greater residential density.

via In San Francisco, the Boom Is Back | SPUR.