As many of you may know, the new senate bill 9 (SB9) went into effect in January 2022. Since then, cities and counties in California have begun implementing the law in different ways. Some have welcomed it, while others have found ways to restrict it as much as possible.

Although there are still some clarifications to be made within the law itself, here is how different jurisdictions are implementing the law and how it affects you. Read on to find out how SB9 laws will affect your development plans.

SB9 Recap

Before we dive into what is new with SB9, let’s recap what exactly it is.

SB9, also known as the California Housing Opportunity and More Efficiency (HOME) Act, is a state bill that allows owners of single-dwelling units to build additional dwelling units on their plots and sometimes split their plots in two. 

For a more in-depth review of what SB9 is and if your plot of land qualifies for it, check out our SB-9 Explained article.


How Jurisdictions Are Implementing SB9

Every jurisdiction (city/county) can allow or obstruct SB9 based on how they implement it. Some cities, like Sunnyvale, are very pro SB9 and have therefore allowed it as is to be implemented into their laws. However, many cities are anti SB9 and have come up with unique ways to obstruct it. There are also rumors of some cities combining ADUs with SB9s to allow more than four units to be built on a lot.

Many of the most restrictive cities have implemented creative laws that make it almost impossible to build an SB9 unit on your property. These laws include things like having to construct a hedge on your property line or requiring that gardens be created on your property. Some are even trying to make the entire city a historic district.

How your jurisdiction implements SB9 law will greatly determine whether an SB9 is feasible for your property or not.


SB9 Obstructions Tactics

Other than normal enforcement restrictions, jurisdictions have gotten creative in how they have obstructed SB9 from taking effect in their cities/counties. There are a large number of cities that oppose SB9, so yours may likely have put into effect one of these tactics to make it as difficult as possible for you to build one.

Here are just a few of the tactics jurisdictions are using to impede this new law.


Different Zoning Laws

The SB9 unit and the primary home should have the same zoning laws. However, some jurisdictions have different zoning laws that only apply to the SB9 (secondary) unit. This means the unit built under SB9 could have different square footage requirements, setback requirements, floor area ratio, etc., than your primary home.

So, for example, your house might be able to be 20 feet tall, but your SB9 secondary unit can only be 15 feet tall under these obstruction tactics.


Overly Burdensome Affordability

Inclusionary ordinances are allowed to be enforced in cities. However, some jurisdictions have made it so that SB9 units have different inclusionary ordinances than the rest of the city. So, for example, some cities require every house in the city to be affordable, and therefore the SB9 units would have to be too, which is fine. Where it becomes burdensome is when cities do not require the primary homes to be affordable, only the secondary SB9 units.


Burdensome Objective Standards

The SB9 law allows for objective zoning standards. However, some jurisdictions take it too far by creating burdensome objective requirements that are almost impossible to meet.

For example, they might require that your SB9 unit matches both of your neighbors’ designs. This is called design matching. If your city as a whole does not require it, only the SB9 does, this can make it impossible to build because your neighbors’ houses could be of different heights with different types of roofs. You cannot possibly match both, meaning you cannot build an SB9 unit.


Excluding Lots Based on Zoning Eligibility

One of the most effective ways that cities are blocking SB9 is by upzoning. Upzoning laws allow cities to bring back some of the power and control into their own hands by excluding lots from SB9 completely based on their zoning eligibility. Here is how it works.

If your lot is zoned for a single-family home and meets all of SB9’s basic requirements, you could build a secondary unit on it. If it is zoned in a way that allows two units (Multifamily) on it that can be conveyed separately, then it is no longer eligible for SB9. This is because SB9 is only for single-family residential plots.

Therefore, some cities like Solano Beach say that if your plot is zoned in a way that would allow you to build a primary house and a secondary one, you do not qualify for SB9 even though you only have 1 residential house on your property. However, some pro SB9 cities like Sunnyvale say that you are still eligible for SB9 under these circumstances. So, it all comes down to how your city upzones.


Other Obstruction Tactics

There are, of course, several other obstruction tactics that cities are practicing. For example, some are requiring development applications to be submitted concurrently with a lot split application. This makes the application process a lot more difficult.

Other cities have put into place clever obstruction tactics like requiring:

  • A large hedge along the property line where you’re doing a lot split
  • Extra second floor setbacks
  • The installation of a 400 square-foot garden
  • Tree preservation
  • Very large street access

All of these tactics will likely not hold up for long as the SB9 bill becomes amended. However, the upzoning laws likely will stay in place. So, if your city is practicing upzoning, it may be hard for you to build an SB9 secondary unit in the future.


Does Your City Oppose SB9?

There are a large number of cities that oppose SB9. Just a few include:

  • Arcata
  • Belmont
  • Cupertino
  • Fillmore
  • Inglewood
  • Lafayette
  • Lakeport
  • San Carlos
  • Santa Clara
  • Ventura
  • West Covina

Many, many more cities oppose this bill and are likely taking action to obstruct it. You can check out the senate analysis of the bill to determine if your city opposes it or not.


Should You Wait to Build SB9?

With the SB9 law passed and jurisdictions finding new ways to impose obstruction tactics on those who want to build SB9s, the best time to build one is now. Since the SB9 law is so new, it will likely undergo many amendments and jurisdictions will find more new ways to make it as hard as possible to build.

So, if you live in an area that is against SB9 and you are positive you want to build one, your best bet is to work with professionals now and get it built as soon as possible. That way you will be grandfathered into whatever new amendment or obstructive tactics that may come.

If you live in an area that is pro-SB9 and you are positive you want to build one, there is no point in waiting either. The only time you should wait is if you are not sure if you truly want an SB9 unit or just an ADU.



Additional Dwelling Units (ADUs) have been around for a while now. We know all the laws and regulations associated with them, whereas legislation is still hashing out SB9. So, besides knowing the laws, what is the difference between the two?

ADUs are small secondary units built on the plot of a single-family home. Sounds similar to SB9 right? The difference is that ADUs have strict size regulations, meaning they are much smaller than SB9s. They face many ADU zoning regulations and rent control laws that differ from SB9s and can not be sold as separate units.

The big difference is that most cities are anti SB9, meaning they will do anything to block the construction of an SB9 unit but will likely allow an ADU. ADUs have grown in popularity in many California cities due to their ability to provide affordable housing to combat the housing crisis. They also don’t disrupt the neighborhood too much since they are small and can’t be rented out short term. So, if you are in a hurry, your best bet is to build an ADU because you will likely face many obstacles with an SB9.

However, if your city is pro SB9, you can benefit from building a much larger unit. You can also take advantage of a lot split and sell it to a developer or develop it yourself. Again though, this is only possible if your city is one of the very few that is not obstructing SB9.


ADU Experts

If you have weighed the pros and cons of an ADU vs. SB9 and decide you want to build an ADU yourself, we can help. Here at Levi Design Build, we are eager to help you build the ADU of your dreams. Our team of experts can help you through the designing, planning, and construction phase of your ADU development to ensure it goes as smoothly as possible for you. Contact us today or check out our free ADU guidebook to see how an ADU can be the perfect fit for you.