SF Apartment : November 2017


As Easy as A-D-U

by Benjamin Farrell

San Francisco’s ADU program allows property owners to increase the number of units in their buildings in response to a citywide housing shortage. It was adopted as an incentive for building owners to make their buildings safer through remedial structural improvements required under the Mandatory Soft Story Program. The structural permit was the qualifier for adding additional dwelling units, but that’s all changed now. This program is applicable to almost all residential buildings in the city, independent of the MSSP. In the next few years, it will alter the city in profound ways, but don’t expect it to be around forever.

The ADU program represents the first time since the good old days after the 1906 fire that regulations around development have become less restrictive. The regulatory language of the Planning Code that most affects residential property owners involves density, exposure, open space, parking, and historic preservation. These are all aimed at restricting development in some way and have shaped the San Francisco we know today. With the ADU program, these rules get turned off, along with the onerous obligations under 311 Neighborhood Notification. This power lies solely with the discretionary authority of the Zoning Administrator, which is the reason the whole ADU program works so well. San Francisco property owners should know the rules and common mistakes to avoid to fully take advantage of the ADU program.

Basic Eligibility

There are several things to consider when evaluating a building for ADUs, like basic eligibility. If you have no-fault evictions in the last five years, or an Ellis Act eviction in the last ten years, you’re not eligible. You can try to add units using the regular planning process, but none of the specific ADU waivers mentioned above will be available. If you’re not sure, go to the San Francisco Rent Board at 25 Van Ness Avenue and check the building’s eviction and buy-out history.

Be aware that there is no language in the current ADU Ordinance 162-17 (or previous versions) that specifically addresses buyout history, but our beloved planning staff regards negotiated buyouts as equivalent to no-fault evictions for the purposes of determining eligibility for the ADU program. This is especially important for buyers intending to develop ADUs in newly acquired properties, since evictions are often disclosed, but buyouts are not. If your development plan is to buy a building and vacate it, you’ll be ineligible for the ADU program. The buyout restriction will change, but for now that’s how it is.

Almost every other residential building in San Francisco is eligible, including single-family houses. The next step is to determine if the physical building can accommodate additional legal units.

Habitability Standards

The space intended for an ADU must meet basic habitability standards. This means a finished floor-to-ceiling height of no less than 7 ½ feet. You will also need natural light through windows equivalent in size to 8% of the floor area (not including kitchens, closets or bathrooms) of the room they serve. These windows must open onto qualified open space or a court. Enclosed light wells rarely make the requirement, unless they are 5-by-14 feet for a three-story building. Windows facing open space on the adjacent property don’t count, but skylights do.

Next you need to check for exposure. The planning code ensures units are not added in overly confined areas. Normal exposure requirements are nearly impossible to meet on a typical 25-foot-wide lot, so they are reduced to a 15-by-15-foot area that is open to the sky. While still hard to meet, added units need this area either wholly within the property or as part of a public right of way (street) or public open space (park, etc.). If you can’t draw a 15-by-15-foot rectangle on the open space within your property, you probably won’t make this requirement and will need to go through a variance process.

Exiting New units need a direct connection to the street, with a travel distance of less than 75 feet. For ground-floor development, this is usually easy; for top-floor conversions, it often doesn’t work. An architect is your best resource, as egress requirements are complex and the SFFD is inflexible in meeting them, even for ADUs.

Note: in San Francisco, garages are only considered legal “exits” if there is a 10-foot-wide path to a normal swinging door, or if there’s a protected three-foot exit path. This is intended mainly for larger buildings with parking garages.

Water-Meter Pressure

All ADUs will trigger a requirement to add sprinklers covering the newly created units. It’s rare that water pressure in the city is too low, but I’ve had two projects that came close to not making it. Again, low pressure might not reach an upper-floor conversion. There is no fix, unless you replace the water main at the street for your whole block (you don’t want that). The pressure check is a service provide by SFFD for a small fee.

If you are adding a unit to a two-unit building, you will change the “occupancy” of the building from R-2 to R-3 (single family to multifamily). In this case, you must add sprinklers to the whole building, which no one ever wants to do. Other requirements may also come into play depending on where you are putting the new unit, but adding sprinklers is the big one. Oddly, adding a unit to a building with three or more units that does not have sprinklers only requires new sprinklers in the added units. Go figure.

Rescue Opening

This catches a lot of potential ADUs. This is a door or window into a room used for sleeping. It must have a direct connection to the street or public space. If the rear yard is more than 50 feet deep for R-2 (or 25 feet for R-3), you can also potentially use that. For smaller yards, the resolution here is almost always a workman’s passage connecting the rear yard to the street. You will not be able to add a rescue opening in an enclosed court or lightwell, even if it’s large enough for the natural light requirement.

Waste Bins

The Planning Department will ask where you intend to store waste bins. There is no language in the ADU ordinance covering this, but it’s a part of the approval process. There are no guidelines, other than they cannot be in public view.


Planning approval ends with a flurry of documents that need to be notarized and recorded. A Notice of Special Restriction is issued, stating (among other things) that the newly created units cannot be used for short-term rentals. Also, building owners will enter a Costa-Hawkins agreement covering the applicability of rent-control measures for the new ADUs only, regardless of the building’s eligibility for rent control on other rental units.

Further Guidance

The Planning Department publishes a handbook for owners to guide them through the process. It’s extremely helpful and includes a couple of typical prototypes that apply to most situations where an ADU is possible. It’s available on their website: sfdbi.org/ADU.

For specific advice, contact an architect who specializes in ADUs. They are the best resource for evaluating a building and exploring options. Once you’re confident that you can add dwelling units, expect a permit application schedule of about nine to ten months: one month for design, four to five months for planning approval, one month for zoning waivers and recorded documentation, and three months for building permit approval and final processing to pick up the permit. Timelines vary but are constantly improving as various departments streamline their process.

ADUs are usually not high-end, luxury apartments. In most cases, they are squeezed into spaces no unit was ever meant to be—but that is the intention of the ADU program. The focus is on quantity, not quality. However, with the right architect, you can create something that is enjoyable and comfortable at a cost that is reasonable and easily recouped within a few years. The wait is worth the double benefit of adding income value to your property and helping the housing shortage in San Francisco.

Ben Farrell is an architect working to make San Francisco better. His experience designing and managing high-end residential projects creates the basis for doing exceptional ADUs on tight timelines and tighter budgets. Visit him at f-a.us