How Many Units Can You Build On Your Single Family Zoned Property?

One question we get from clients a lot is about the number of units they are allowed to build on their lots. With so many regulations being released every year, it is easy to lose track of the most up-to-date ADU laws. In this article we are going to guide you through ABCs of the planning process and dispel some common myths about ADU construction.

Let's start out by looking at a single-family residence with just one existing house on it. In 2023, if you are trying to build an ADU/ JADU combination on such lot, you are allowed to construct one ADU and one JADU by right. The ADU can be a detached ground-up construction, an attached garage conversion, a detached garage conversion or any variation of those things. You will need to make sure you stay within setback and maximum height requirements for your jurisdiction. Keep in mind that when building a JADU, it cannot exceed 500 sqft, must be fully enclosed in the single family residence, may have its own sanitation provisions or may share them with the SFR. In addition, a JADU ties the owner to the property, as they must be living either inside the JADU or in the main unit.

After Senate Bill 9 was approved on September 16, 2021, a lot of people turned their attention to it and labeled it as a game-changer for the housing industry of California. This bill only applies to single family residences. It limits homeowners as to the extent of demolition they can perform on previously occupied properties. Two key provisions were announced in that legislation:

1. Lot split.

- Allows homeowners to split their existing single-family lot into two smaller lots (cannot be more than 60% and less than 40% of the total lot area or smaller than 1,200 sqft) and treat each lot as its own single-family "sublot".

2. Two-unit development.

- Allows homeowners to build two units on their lots. ADU/ JADUs are not considered units.

Combined, these two clauses of SB-9 will allow homeowners to build up to 4 units on their lots but more on that will follow. First things first, before you start planning out your project, you will need to check if your lot qualifies for SB-9. Go to Zimas (http://zimas.lacity.org/), enter your address, scroll down to "Planning and Zoning", click on the line that says "SB 9 Eligibility", and read through the window that opens.

Secondly, let's discuss some misinterpretations of the law. This senate bill includes a few new key aspects that some people did not get right. For example, some claimed that the bill permitted construction of up to 6 units on a single family lot by way of applying the SB-9. This is not accurate. To their defense, the bill does seem confusing, so we had to go straight to the source for some clarifications. After a lengthy email exchange with the city of Los Angeles Department of Planning, our team was able to gain a better understanding of this piece of legislation. The following 3 scenarios should be reviewed to exemplify the bill:

1. Only an urban lot split is applied to a single-family lot eligible for SB-9.

For this scenario, you are allowed to build a maximum of two units on each lot for a total of 4 units. ADUs and JADUs will count towards the limit. Each of the resulting lots will be assigned the same zoning designation as the original lot. The existing single-family residence will need to be wholly located on one of the lots.

2. Only a two-unit development is applied to a single-family lot.

In this case, a maximum number of units that could be built on one lot are also 4. You are allowed to build another unit in addition to the existing one, plus another ADU and a JADU as long as you comply with all requirements set forward by the local building department.

3. Both a lot split and a two-unit development are invoked.

Construction of an ADU or a JADU is not allowed. Each new lot can get a maximum of two individual units for a total of 4 units combined.

To sum it up, if you are trying to maximize real estate on your property, you should consider utilizing provisions of the Senate Bill 9. We can perform a thorough study of this potential project for you based on your needs and goals.

If something in this article is unclear or if you need further explanation, just reach out to us via the contact form or by calling (323) 640-9149.