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Amidst a Crisis, San Francisco Needs Secondary Dwelling Units

Amidst a Crisis, San Francisco Needs Secondary Dwelling Units

Affordable housing is scarce in the city of San Francisco. Low-income residents and students a-like struggle to get by in a city that is so full of opportunity, yet so economically biased.  One viable option towards solving this crisis is utilizing secondary dwelling units, aka “in-law units,” as a way to provide living opportunities that

by Rob Poole January 15, 2013 8 comments

Affordable housing is scarce in the city of San Francisco. Low-income residents and students a-like struggle to get by in a city that is so full of opportunity, yet so economically biased.  One viable option towards solving this crisis is utilizing secondary dwelling units, aka “in-law units,” as a way to provide living opportunities that are cheap, sustainable, and convenient.

These units are located on the same lot as the primary unit and they may be connected to the main house or a completely separate structure.  Although they are legal in San Francisco, strict zoning requirements and neighborhood concerns make it hard to get them built, legally. As a result, illegal units are dispersed throughout the city.
Small detached unit located behind main house

There are too many logical reasons and too few legitimate concerns to not support these units.  They don’t require extra land, new homeowners can benefit from the extra income from the tenants, and they can provide family stability. Concerns over the need for extra parking and the added density do not fit in with the times.  Frankly, we can’t rely on cars like we used to and urban cores must become more dense if they are to support growing populations.

Small attached unit located underneath the main houseLittle research has been done on using secondary units as a way to provide more affordable housing and past pursuits to make this idea become a reality have been stifled by lack of support. A 2001 report from SPUR proposes four solutions for the development of these units:

  1. Allow units without parking near transit;
  2. Build more for the elderly and disabled;
  3. Reclassify single-family areas to RH-1-S (single family units with one minor secondary unit);
  4. Allow buildings of historical and architectural significance and put the revenue towards preservation.

San Francisco’s urban planners should advocate this unique home design through rezoning in the city’s western districts, where single-family homes are prominent, and by developing specific criteria for buildings codes and licenses.

What solutions do you propose for solving San Francisco’s affordable housing crisis?

Credits: Images copyright of Robert Poole. Data linked to sources.

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Rob Poole graduated from UC Berkeley with a degree in Anthropology and a minor in City and Regional Planning. He grew up in San Diego, but now resides in San Francisco. He currently works at a non-profit organization in San Francisco that advocates f...

  • A great way to add an extra unit (and one I’m personally looking into) is to convert an underutilized garage into a studio apartment. It’s often easier than you think and a great return on investment.

  • Hey Alex,

    Thanks for the comment. I have heard about people doing this and I am sure there are plenty in San Francisco, although most of them are probably illegal. Portland actually provides a great model for the advocacy of secondary housing units. There needs to be zoning and building codes to provide guidelines for this development. Right now the zoning requirements are so strict that it is too hard to get these built legally. A lot of this is stemming from the conflict between the need for more density in San Francisco and the concern for the preservation of neighborhood character, which in this case is areas comprised of single-family units, where space is valued.

  • Tim Colen

    Good article, Robert.
    SF is in a weird situation where secondary units have been illegal for decades, yet are being built by the thousands. The resistance to them, particularly by conservative homeowners on the west side is intense and has prevented any discussion or solutions. It appears, however, that the demographics on this topic are changing and support for them might be increasing. Let’s hope so!

  • Thanks for the comment, Tim.
    This topic has brought my interest towards the battle between the planning department and these conservative homeowners. The 2009 Housing Element is a perfect example of this. It is definitely something I will be writing more about in the future.

  • Fred Dawson

    Although I don’t live in SF (I live in Toronto)you raise a very important issue in your article- the need for more affordable housing. In Toronto people build rental units in their basements to provide income to help offset the high cost of buying/paying for a home. The challenge with these units is that they usually don’t meet building code requirements often at the expense of safety for the occupants. I suspect the illegal secondary units in SF don’t meet building code requirements in many instances. I think cities need to accept that more affordable options need to be made available and to streamline the process to bring them on line. That said, they also need to create comprehensive guidelines for their construction and to ensure that existing units provide a safe and healthy environment for occupants. I think the biggest hurdle is neighbourhood opposition to secondary units. They are often viewed as unattractive and the occupants are seen as transient and undesirable.

  • Hi Fred,

    Thank you for the comment. I completely agree. It really comes down to the cultural core of these communities. These neighborhoods in San Francisco are primarily comprised of single-family homes, which historically are known as places to raise families. This idea is still alive in the minds of many and incorporating that living concept with small secondary units, which will probably attract an entirely different demographic, is troubling to them. This is just thoughtful speculation. But I actually was in the Outer Sunset District in San Francisco a couple of days ago and frankly, I understand why people would want to keep it the way it is. Unlike the eastern half of the city, it’s spacious and more relaxed. I am sure residents are concerned they will lose these characteristics with new developments.

  • Peter

    This call might be at right time: willing political mindset AND changing demographic. SF has long had the RH-1(S) district which allows a small unit to a basic single-family context. The problem is not so much building code as it is parking space: the single-family neighborhoods lobbied hard to make sure a second unit has a second parking space, and since the ideal second unit area IS the garage, carving the second unit out of the very garage space where the added parking would go has been the catch-22. Today, with many new residents having no interest in owning a car and the newer demographics (Asian/urban) of single-family neighborhoods being less averse to density, there’s less phobia about car parking space than 40/60 years ago when codes were drafted.

    The best-chance solution seems to revise RH-1(S) to allow no parking, roll out a “pilot” area on the highest-frequency transit lines where cross-town lines hub, and promote as an affordable housing solution for both the homeowner (whose mortgages are off-set with rental income) and the small-unit tenant who no longer subsidizes a garage. After a year’s demonstration, the program is tweaked as needed and expanded if ready.

  • Robert Poole

    Great idea Peter! San Francisco is certainly becoming more open-minded to urbanism. Starting a pilot program with secondary units along transit corridors would be a great start. Unfortunately, the west side of the city is far less receptive to change than the downtown neighborhoods. But residents must understand that San Francisco is facing a housing affordability crisis and it must do whatever it can provide more affordable options for those who want to live in the City.

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