The “wand” here is zoning. All the pale yellow areas in this map are zoned to allow only low density residential, mostly one unit per lot: <a href="http:&#x2F;&#x2F;www.sf-planning.org&#x2F;index.aspx?page=1569" rel="nofollow">http:&#x2F;&#x2F;www.sf-planning.org&#x2F;index.aspx?page=1569</a><p>If you re-zone some significant portion of the western and southern 3&#x2F;4 of San Francisco by zones that allow for e.g. the construction of 4–5 story low-rise apartment buildings (ideally allowing ground floor retail), there will be room for dramatically more housing units to be built.<p>Developers are currently rushing to build on every bit of available land in SF that allows medium density construction (all the bits of that map that aren’t pale yellow). All of the parking lots, warehouses, and little one-story buildings in such areas are being converted to luxury condos at maximum speed.<p>With better transit and municipal planning throughout the Bay Area, there are many places where it would be possible to dramatically expand housing stock and bring housing rent down to more reasonable levels.