SB 9 Urban Lot Split
for Duplex orÂ
Single Family
What you need to know
California recently passed a law (SB 9, 2021) which mandates that local municipalities allow an existing Single-Family lot to split into 2 separate lots or construct a duplex on the lot. Each lot can only have 1 main residence, and one ADU (per the ADU law), 1 duplex on each lot, or a combination thereof, for a total of 4 units on 2 lots. What this means for you is if you own a large single-family lot with an existing house you are more than likely able to split your lot and build a second house much easier that ever before.
In order to split your lot into 2 separate lots, the size of your lot must be large enough to accommodate another single family home while still complying with the current City Zoning frontage and setbacks on all sides of the property. This usually precludes "tract homes" from splitting as these lots are usually the smallest possible. Additionally, the City may impose a minimum lot size smaller than the minimum lot size required for the current Zone.
The 2 lots must be roughly equal in size (between 50/50 and 60/40) and both must have direct access to the street fronting the original house. An easement for access is a possibility if direct access is not feasible. If you wish to split your lot into irregularly shaped lots or more than 2 lots, you may still be able to do so using the existing Subdivision process (known as a Tentative Parcel Map).
To add an ADU, you must comply with certain requirements, see our ADU consulting service.
If you have a Home Owner's Association (HOA) you may be severely or possibly barred from developing using SB-9! You still may be able to build an ADU, see our ADU consulting service.
Your new Single Family home must comply with any parking requirements, including providing off-street parking in a garage or driveway.
You must owner-occupy the existing home, or move into the newly constructed home for a minimum of 3 years in order to qualify. This eliminates investors who will not occupy either property from taking advantage of this law. Investors can still Subdivide lots with a Tentative Parcel Map.
If your existing home is identified as "low-income" or has tenants that paid rent within the last 3 years, you may not qualify. Contact your local City Planner to discuss.
What to expect:
While the subdivision of your lot is now easier than ever before, the permitting of the new structures still requires the same review process as a new Single Family home would.
At the least, your project will require a Tentative Parcel Map, and a Grading and Drainage plan. Other plans may be required (such as Retaining Wall plan, Street Improvement plan, and Utility plan). We will work with the City to determine what is required.
You will need an Architect to provide plans for your new home. Or you may wish to purchase a pre-fabricated home. Either way, the plans must be reviewed for compliance with Building Codes. If you do not have an Architect but want one, let us know!
You will be required to hire a Land Surveyor to find and identify your property lines. They will also help with establishing the new lot line that will separate the two lots. If you do not have a Land Surveyor, we can recommend one to you!
A surveyor should also be hired to perform a topographic survey to identify the elevations of your land. A Grading and Drainage plan cannot be completed without one.
Once you have those to items addressed, we can begin our plans. We can work with your Architect and Surveyor to coordinate our plans, and address any design issues that come up.
The new residences will need utility connections (sewer, water, electrical, telephone, cable). We can provide designs for the first two (sewer and water) but you will need to hire a separate consultant for the electrical, telephone, and cable.
From start to first submittal can take the longest since all of this information must be established before plans can be completed. That said, much of this information is available now online or quickly by phone. We anticipate we can turn around your project in just a couple of months.
Who needs this service:
Property Owners & Investors - Unless you owner-occupy one of the residences, you are exempt from taking full advantage of this new law. Contact us regarding our Tentative Map service!
Land Developers - Unless you owner-occupy one of the residences, you are exempt from taking full advantage of this new law. Contact us regarding our Tentative Map service!
Civil Firms - Allow us to help you with your over-loaded staffing needs.