A proposal for a 50-story residential high-rise tower in San Francisco’s Outer Sunset District is currently before the San Francisco Planning Commission. What draws attention is its size in comparison to its surroundings and location, seen in the following photos. There is always a first in any area where new high rises are built like in Miami Beach and the tall buildings at ring nodes on the Houston Outer Belt. Below is what has been presented to the Planning Commission:
How is it possible to build 50 stories tall in a 100-foot height limit zoning district? The logic is as follows in the illustration supplied by the applicant:
The first diagram illustrates what existing San Francisco zoning allows on the site. The lighter yellow addition is what state legislation allows as an increase when affordable units are added. The remaining diagrams simply stack the massing in progressively different configurations of the same square footage claiming that the state legislation allows the height limit to be broken.
There has been a good deal written about this proposal and it has stirred up some interesting public comments. One of the most common concerns is about building a tower on sand. This type of building of course is not built on sand but rather through sand with driven piles. The piles depend upon surface friction to resist the weight of the building above rather than piers which depend upon bearing on strata (bedrock) to support that weight (see illustration to follow). The more piles driven the more surface area of friction, the more weight the piles can support. The new building does not depend upon bedrock to resist the weight, so the concern of building on or through sand is mitigated.
Also, mistakenly commenters attribute how this tower could be a disaster like the Millenium Tower in downtown San Francisco which is tilting for different reasons (possibly a subject for another blog post). Hundreds of high-rise buildings have been built in this manner for over a hundred years including Miami Beach where engineers have this figured out.
Putting this aside, another concern is the lack of private parking, an issue that would be important to me as a homebuyer. All 200+ parking spaces for the 700+ units are for shared car services. There are several new residential towers in downtown San Francisco with no private car parking, but where there are more transport connections. There are however a few San Francisco urban planners promoting statistics to support the claim that there is a market for those residents who wish to live without a private car. Clutching their pearls as one post noted, they point out that there are too many privately owned cars in SF and claim that car ownership is diminishing. The statistic they use is that “only” 54% of the total population in San Francisco own a car. But if children are included in the total population of San Francisco, the percentage of car ownership should be much higher. The percentage is even higher when one takes the number of households in San Francisco (362,141) and divides it by the 472,000 people who own cars in San Francisco, meaning each household owns 1.3 cars, not .54 cars as suggested above.
Furthermore, accounting for households such as mine, where my spouse and I each own a car, our household is a 2.0 car household. This would then account for a few others that have 0.0 cars to average out at 1.3 cars per household. Indeed, there are a few households that do not own a car, but the number is much less than planners claim. Another point made by planners is that apartments are bought buy in San Francisco for investment purposes and are never lived in or rented out, over 10,000 by some estimates, and as high as 40,000 by others.
Still, I am skeptical about the marketability of units at 2700 Sloat with no parking for private cars. I have lived in several different mid-rise and high-rise residential buildings in San Francisco, and all had parking in the building. There is now legislation in California that mandates current minimum parking requirements be abolished for housing projects at and near transit hubs. This is now a common practice in Los Angeles and the first type of this project is being approved currently in San Diego to make the living unit less expensive. Such buildings have sold well here in San Francisco downtown, but it will work at 2700 Sloat is still unknown. Some parking comments published on the YIMBY website:
Public comments have surprisingly not centered on the parking issue, but more on the impact it will have on the neighborhood.
A reasonable comment follows:
All in all, many believe this proposal is not serious but a starting point for negotiation. It raises some policy issues around density that deserve thought. As in Angela’s response to Joanne below: the housing crisis is real.
Blog post written by David Tritt, Senior Architect.
