ZONING FOR MORE HOUSING
PROPOSED CHANGES TO SAN FRANCISCO'S PLANNING CODE AND ZONING MAP

A SPUR REPORT
by the SPUR housing committee
Adopted by the SPUR Board of Directors
February 18, 1998
Introduction
San Francisco has a crisis in the availability and affordability of housing, causing rents and home
prices to escalate rapidly in this time of economic growth. Unless substantially more housing is
constructed in this City to meet the ever-growing demand, rents and home prices will continue their
escalation at accelerated levels, our City's economic and cultural diversity will suffer as middle
income residents are forced out, and the Bay Area's greenbelt will be sacrificed to urban sprawl.
Businesses will also be reluctant to locate and expand here if their employees cannot afford to live.
SPUR has analyzed the various impediments to the production of more housing in this City, with
the objective of identifying specific recommendations for reforms within the power of local
governmental bodies to implement. We assumed the existing meager level of federal and state
support for affordable housing subsidies will remain, and rather than focus on ways to increase
such subsidies, focused on removing other impediments to the delivery of housing, both affordable
and market-rate.
Last month's SPUR Report looked at one new neighborhood we should consider as a major
housing development opportunity. This report looks at another major topic: a shortage of land
available for new housing and unduly restrictive density limits on other land currently zoned for
housing. As the City has down-zoned existing residential neighborhoods to preserve their character,
very little other land has been identified to fulfill the demand for new housing sites.
To the address the issue of land availability and density, SPUR recommends that the City undertake
the following six actions. :
A. Rezone underutilized land currently zoned for industrial and commercial uses to
encourage moderate to high density housing.
B. Permit density bonuses City-wide for projects that provide affordable units.
C. Increase heights and densities along neighborhood commercial corridors and
major transit routes.
D. Revise height and bulk limits in certain residentially zoned districts so that they
are better synchronized with Building Code height restrictions and building
envelopes that are feasible to construct.
E. Permit Planned Unit Development approvals for residential and mixed use
developments on lots smaller than a half-acre and within the downtown area.
F. Increase the housing density permitted on downtown lots without the need to
acquire transferable development rights (TDR's).
Each of these recommendations can be implemented through amendments to the City's zoning map
and Planning Code. Those amendments will require action by the Planning Department and
Commission, Board of Supervisors, and Mayor to implement.
A. Rezone underutilized land currently zoned for industrial and commercial
uses to encourage moderate to high density housing.
A large majority of the vacant and underused land in San Francisco is currently zoned for industrial
uses (M-1 light manufacturing or M-2 heavy manufacturing), with low height limits, making
housing a disfavored land use. Only live/work projects, which are currently supposed to be reserved
for occupancy by artists only, are permitted in these industrial lands, leading to a boom in the
construction of loft-type live/work units, but a shortage of land available for more conventional
housing construction.
All M-1 and M-2 areas of San Francisco should be re-examined to determine whether some
portions of those zones can be changed to residential or mixed use zoning, with appropriate
adjustments in height limits. The zoning designations for these areas date back to 1935, when San
Francisco's job base was largely industrial. The job base has changed over time, but the zoning has
not, leaving many hundreds of acres of land zoned exclusively for heavy industrial uses that in all
likelihood will never return. The types of "industry" that are attracted to San Francisco (electronics,
multi-media, printing, business services, etc.) are not the types of smoke-stack industries of the past
that needed to be segregated from residential development. Rather, housing can co-exist with these
newer, cleaner industries, which often require less land than older industries.
An example of how this strategy might provide incentives for private developers to provide housing
on a 10,000 square foot lot currently zoned M-1 with a 50-foot height limit is as follows: Under
current zoning and height controls, up to about 30 units could be built, but would require conditional
use approval (which is uncertain and thus risky for any developer), and the new housing could be
located next door to a future noxious heavy industrial use, since those uses would continue to be
permitted in the M-1 zone. Most developers would not take these risks. Were the same lot zoned
RC-4 with a 84-foot height limit, about 50 units could be developed, and the developer would be
assured that future neighbors of the project would be compatible with residential development.
Intervention by the Redevelopment Agency often will be necessary to create the types of
infrastructure improvements necessary to support new residential neighborhoods. The Agency is
well-equipped to orchestrate the creation of new neighborhoods through its powers of land
assembly and the issuance of tax increment bond debt to finance essential infrastructure. MUNI
service to these areas may also need to be augmented.
SPUR's March 1998 report, The Future of the Central Waterfront, was a case study of this notion.
It examined the Central Waterfront between Mission Bay and Islais Creek, one of the largest
underutilized areas of San Francisco, and concluded that up to 12,000 housing units could be
developed in that area with the right combination of rezoning, public intervention, and private
investment. These strategies apply equally to other areas of San Francisco.
The Planning Department has just embarked on a land use inventory study of San Francisco. That
study must address these issues.
B. Enact a City-wide density bonus for affordable units.
State law requires local jurisdictions to provide density bonuses to developers in exchange for
providing affordable units. Yet, San Francisco has never implemented this legal requirement except
on a case-by-case basis, requiring a time-consuming legislative action for every density bonus
considered, resulting in very few additional affordable units. We cannot afford to stifle the
production of additional affordable units in this way.
To meet State law, the City should enact a City-wide density bonus program that would permit
builders, within the existing height and bulk limits, to increase allowable density provided a certain
percentage of the additional units (above the base density limit) are affordable units. Developers
would be willing to voluntarily construct additional affordable units when their marginal costs of
doing so are equal to or less than the price at which they could rent or sell the units to low-income
households. A density bonus would also make it more feasible for developers to meet the City's
current policy requiring 10% of units in market-rate projects to be affordable.
This reform would also permit non-profit
developers of low-income housing to
produce more units on the a particular
piece of land. When density is increased,
the marginal costs per unit are lower, since
the land prices, soft costs, and foundation
costs can be amortized over more units.
Decision-makers will need to abide by this
bonus program and permit the additional
units to be built in the face of the
opposition that certainly will be expressed
by some neighbors, who frequently
oppose any new developments, much less higher density low-income units. To avoid potential
opposition, perhaps this Code change could at least initially not apply in very low density zoning
districts, excluding, for example, all single family zoning districts.
C. Increase height limits and densities along neighborhood commercial
corridors and major transit routes, encouraging housing over retail.
There are numerous opportunities for the provision of higher density housing along
moderately-scaled neighborhood commercial corridors and major transportation routes, such as
Geary Boulevard and Third Street, both stand-alone and above ground-floor retail. These areas
already have in place all the urban infrastructure needed to support relatively intense residential
development (transit, retail, community facilities, etc.) and are generally at least slightly removed
from surrounding low-density neighborhoods. Moreover, San Francisco's General Plan calls for
such increased density along transit routes, but those policies have never been implemented.
It is time to begin implementing these General Plan policies. With even a 10-foot increase in height
limits in many neighborhood commercial districts (from the current 40 feet to 50 feet), significantly
more residential units could be created with less expensive wood-frame construction methods, which
allow four floors of residential construction above a retail and parking podium.
In mixed retail/residential projects, the costs of land and construction overall could be cheaper.
Existing retail areas should be studied individually to determine suitable locations for encouraging
the addition of several floors of residential on top of commercial uses, including neighborhood
shops, supermarkets, big box and shopping center-type retail, and institutional structures, such as
post offices.
Given the fact that most commercial areas are located on good transportation routes, a reduction in
parking requirements should be encouraged, particularly given the fact that commercial and
residential parking can often be shared.
D. Revise height and bulk limits in certain residentially zoned areas so that
the height and bulk limits are better synchronized with Building Code height
restrictions and building envelopes that are feasible.
Currently, there is not a rational relationship between the height limits set forth in the zoning maps
and Building Code height restrictions. Applicable height limits should be revised to better reflect
Building Code standards.
For example, the current 80 foot height limits in some residential zones should be changed to 85
feet. The San Francisco Building Code allows buildings with a height to their top occupied floor of
75 feet or less to be designed with less expensive low-rise standards. As residential buildings
typically have floor heights of ten feet, an overall permitted building height of 85 feet (75 feet to the
last occupied floor plus ten foot story height) would be required to fully maximize the provisions
allowed in the building code. An 85 foot height limit in lieu of 80 feet would permit one additional
floor at maximum cost efficiency.
Certain bulk limits also strongly discourage new residential construction, by requiring buildings to
be so slender that it is infeasible to construct them. Typically, at least 10 units per floor (about
12,000 gross square feet) must be built in a high-rise residential structure to be feasible, since each
floor requires two elevators and two enclosed exit stairs. Yet, the bulk limits in the many districts of
the City that permit high-rise housing require floors as small as 6,400 square feet, about half what is
practical to build. The City should re-examine the complex bulk controls set forth in the Planning
Code so that those controls do not unduly inhibit needed residential construction.
E. Permit planned unit development approvals on lots smaller than a
half-acre.
Currently, the Planning Code permits projects to be considered as planned unit developments (a
flexible planning category not bound by strict zoning rules) by the Planning Commission only if the
lot size is a half-acre or larger and outside the downtown. The PUD process frequently permits
more units with a better, more feasible design, because the strict density, rear yard, setback, parking
and other requirements of the Planning Code, that were designed for the typical 25 x 100 foot lot,
can be relaxed. At the same time, a PUD must be approved as a conditional use by the Planning
Commission, giving the commission discretion to examine and regulate the overall design of each
PUD, and to impose conditions requiring about 10% of the units to be affordable.
Given the small size of many development lots in San Francisco, limiting the PUD process only to
lots of a half-acre or larger is not necessary or desirable. The threshold should be reduced below a
half-acre, perhaps to lots of 10,000 square feet or more. Similarly, the rather arbitrary prohibition on
PUD's in downtown C-3 districts should be lifted.
An example of how this Code change could result in more housing units (and more affordable
units) is as follows: Under the current Code, on a 10,000 square foot lot zoned RM-3 (a typical
zoning category for moderate density districts), up to 25 units could be built. If the builder were
allowed to apply for a PUD on the same lot, up to 49 units could be developed, 5 of which would be
required to be affordable units. The builder would need to go before the Planning Commission for
conditional use approval, so that massing, design, parking and other neighborhood concerns could
be addressed.
F. Eliminate the requirement in downtown (C-3) zoning districts that
housing projects exceeding the base density limit purchase TDR's
(transferable development rights).
When the Downtown Plan was enacted in 1985, it intentionally limited the base density allowed in
the downtown C-3 districts so that developers of large projects would need to purchase transferable
development rights (TDRs) from historically significant structures that were protected from
demolition. Unfortunately, this requirement applies to housing as well as commercial space, so that
any housing project exceeding the relatively low base FAR (floor area ratio) in a C-3 district can be
built only if the developer buys TDR's from a nearby commercial building that has been rated as
historically significant.
This requirement applies only in C-3 districts and has discouraged the construction of any new
high-density housing in these districts, the exact location where high density construction is
encouraged, by adding a significant cost to each project. The Planning Code should be amended to
not impose density limits on residential uses in C-3 districts, but simply limit density through height
and bulk regulations (such as is employed in the Rincon Hill and Van Ness Plan areas). This Code
change would eliminate the disincentive that now exists to build housing in C-3 districts.
This Report was drafted by the SPUR Housing Committee, S. Osborn Erickson and Tom
Jones, co-chairs. Other contributors were Mary Gallagher and Steve Vettel. The Report
was debated, refined and passed by the entire SPUR Board of Directors on February 18,
1998. It represents the official policy of SPUR.