Common Questions on SB-9 and ADUs

A Conversation with Seb Frey, a local santa cruz real estate agent

Who are you, and what is your professional background?  What work do you do today?

My name is Anais Schenk and I have a masters in urban planning. I specialize in transportation and land use planning. Today I have a small business called Om Design. We do building design and help homeowners and contractors get their building permits. We also work with real estate agents and investors to assess properties for their building potential.

What is California’s SB-9 law?

Senate Bill 9, or SB-9 is a new piece of legislation that allows property owners in California to subdivide a single-family zoned lot and build up to 4 units. There are some requirements – the lot has to be in an urban area and cannot have environmental constraints such as fire hazards, wetlands, flood zones, etc. There is a full list of constraints available as a form handout from the City and the County of Santa Cruz.  However, most parcels in urban areas qualify.

How did SB-9 change the game when it comes to building an ADU in Santa Cruz County?

Because SB-9 allows for the subdivision of a property that previously could not be subdivided you can now build up to two single family homes and two ADUs on that property. This assumes that you go through the subdivision process and are playing the long game with this property.

What is the difference between building an ADU via SB-9 versus outside of that process?

Comparing the ADU regulations and SB-9 is a little like comparing apples and oranges. The two sets of regulations can be combined to create a better investment for your property, but they do different things for your investment. SB-9 allows you to subdivide a property and build up to 4 units between the two new properties whereas the ADU regulations normalized and streamlined the construction of ADUs on single family lots.

What are the zoning requirements?

The property must be zoned for single family use.

What are the permitting processes, timelines, and fees?

The process for SB-9 varies substantially from city to city and quite frankly has yet to be fully fleshed out in most places. The timeline for building permits is supposed to follow the standard review process regulations which is 30-90 days, however there is no definitive timeline for the subdivision process. Using SB-9 is definitely playing the long-game. Once the subdivision and building application is approved the property owner has to commit to using one of the homes as their primary residence for three years.

What are the most challenging site conditions that make building an ADU difficult?

I think these would be the same considerations that would make building a single family home difficult. The presence of hazards such as fire, flooding, etc as well as environmentally sensitive habitat.

Are there Design, Size, and Parking Limitations?

Yes, and the answer to this question depends on whether you are building ADUs or single family homes and whether or not you are utilizing SB-9. Both ADUs and any building constructed under SB-9 have reduced setbacks of 4 feet for the rear and side yards. The ADU laws state that any city or jurisdiction has to allow an ADU of 800 square feet. However, most cities allow larger ADUs particularly if you are building a unit with two or more bedrooms. The SB-9 law has a cap of 800 square feet for multiple single-family homes. So the most favorable combination of these laws in terms of getting the most square footage out of your property is usually to use SB-9 to subdivide the lot and then apply for a building permit for a single family home with ADU on the new lot. There are many considerations when looking at these two sets of laws to determining your building envelopes but this combination seems to be the one that yields the most square footage. There are also height considerations that are somewhat complex, but generally speaking an ADU under 16 ft is allowed. Parking is not required for ADUs within a half mile of a transit stop and the SB-9 parking requirements are one parking space per unit.

What is the fastest & least expensive ADU to build?

A 500 square foot attached ADU is considered a junior ADU or JADU and has the least amount of fees associated with it. It will typically get through a review process a little quicker than an ADU simply because the project is usually more straightforward. An ADU that is 750 square feet or less is also usually fairly affordable because there are more fee reductions than an ADU that is over that size.

How long does a typical ADU take to build, and how much does it usually cost, once a permit is approved?

This is not an easy or quick question to answer. I have a blog post on this topic on my website with more detail, but I can give you a little information here. We have started to recover from pandemic pricing, so the costs have become more affordable now. The average construction price can range anywhere from $200,000 to $400,000, or another way to look at it is between $350 and $650 per square foot depending on the types of materials and the methods of construction you are using. There are a host of soft costs to take into account including the design, engineering, permit fees, and other consultant fees. A rule of thumb is to budget for 10-15% of your construction costs for soft costs. There are a few ways to save money including building a smaller ADU as mentioned before. You can also save a fair amount of money by hiring a building designer rather than an architect. You actually don’t need to have an architect on most small residential projects. If you are building your dream home and have a healthy budget by all means hire that architect, but if you are looking for small home design or simple remodels you’ll save money and be just as well served by hiring a professional building designer.

What do most people find surprising or difficult about the process of building an ADU?

There are two things that usually catch people off guard. The first is the cost. Somehow people got the idea that an ADU could be built on a shoestring budget. While they are less expensive from the permitting perspective its still new construction and between inflation and increasing costs of labor you’re still looking at spending a couple hundred thousand. The second thing that people find challenging is the permit process. Its supposed to be a streamlined process and while some cities have really made the effort to streamline it we are still seeing permit timelines as long as 6 months to 1 year. There are a lot of small ways that time builds up. For example, cities don’t start the clock ticking on your project until you have completed the intake process and paid your initial fees. I’ve seen the intake process take weeks to complete depending on the city. Some cities also parse out the planning review process from the building review process which adds a couple months up front to the process. There are a lot of small ways that the timeline can be impacted and elongated by the reviewing agency.

Is there anything people should know about building an ADU in Santa Cruz that we haven't covered?

One thing we haven’t covered that I think is a really neat aspect of the ADU law is that you can convert existing nonconforming accessory structures or spaces into ADUs. So for example, if you have a detached garage that doesn’t meet the 4 foot setback requirement you can still convert that to an ADU and add up to 150 square feet to it.