Senate Bill (SB) 9 (Atkins), signed into law by Governor Newsom on September 16, 2021, allows property owners within a single-family residential zone to build two units and/ or to subdivide lot into two parcels, for a total of four units. Some details of the legislation are still unclear as some provisions are difficult to interpret and the State is still working on their guidance. The affected State legislation is the additional Government Code Sections 65851.21 and 66411.7, and the amended Government Code Section66452.6 (Subdivision Map Act).
The bill requires approval of the following development activities:
• Two-unit housing development – Two homes on an eligible single-family residential parcel (whether the proposal adds up to two new housing units or adds one new unit to one existing unit). A MDUD is a development resulting in no more than two dwelling units on a single lot, inclusive of new and existing structures.
• Urban lot split - A one-time subdivision of an existing single-family residential parcel into two parcels. This would allow up to four units (unless a jurisdiction decides to allow additional units). An Urban Lot Split (ULS) is an action that divides an existing single premise into no more than two separately conveyable lots.
Answer these few questions about your project to find out if you may qualify to get advantage of the benefits California offers to the home owners who want to add more units on their property.
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Regulations that Apply to both MDUDs and ULS Projects
An MDUD/ULS is permitted on a lot zoned for single dwelling unit development but not multiple dwelling unit development. Specifically, it is allowed in zones where the Use Regulation Tables identify an MDUD allowed as a Limited Use: RS, RE, RX, and RT zones and Planned District Zones that permit single dwelling unit development but not multiple dwelling unit development.
Check in which Zone your property is located at Zoning.
MDUDs/ULSs are not permissible on certain premises. For example, they are not allowed if any portion of the parcel is located in or contains any of the following:
Prime farmland or farmland of statewide importance;
The Very High Fire Hazard Severity Zones, unless the development complies with Chapter 7A of the California Building Code;
A hazardous waste site, unless the site has been cleared for residential or mixed uses;
Special Floor Hazard Areas, unless the premises have been subject to a Letter of Map Revision prepared by the Federal Emergency Management Agency (FEMA) and issued to the local jurisdiction or the premises meet the FEMA requirements necessary to meet minimum flood plain management criteria of the National Flood Insurance Program;
A delineated earthquake fault zone, unless thedevelopment complies with applicable seismic protection building codestandards;
A regulatory floodway as determined by FEMA;
The Multi-Habitat Planning Area (MHPA) of the MultipleSpecies Conservation Program (MSCP) Subarea Plan;
Environmentally Sensitive Lands conserved bydedication, a covenant of easement, or conservation easement;
A historic district that is a designated historicalresource or on a property containing a designated historical resource;
A development that requires demolition or alteration ofa dwelling unit that contains rent-controlled housing or a dwelling that atenant has occupied in the last three years
A development that requires the demolition oralteration of a dwelling unit that is subject to a recorded covenant,ordinance, or law that restricts rents to levels affordable to persons andfamilies of moderate income, low income, or very low income;
Premises with SRO hotel rooms/dwelling units that werewithdrawn from rent or lease in accordance with California Government CodeSections 7060 through 7060.7 during the 15 years preceding the applications; or
A development that requires the demolition of more than25% of the existing exterior structural walls of a dwelling unit that a tenant has not occupied in the last three years.
Floor Area Ratio (FAR)
Development that involves an Urban Lot Split and construction of a MDUD shall comply with the FAR of the underlying zone unless the second dwelling unit results in the lot exceeding the FAR in the underlying zone. The second unit in this instance, is limited to800 square feet.
Find out if your project qualifies for streamline permitting under Senate Bill 9 (SB9) to get the permits fast
Development and Zoning Standards for MDUD
If a dwelling unit already exists on the lot, the second primary dwelling unit can be no larger than 800 square feet if the parcel is non-compliant with development regulations such as the FAR in the underlying zone. The development shall otherwise comply with the development regulations in the underlying zone.
An MDUD shall not be rented for fewer than 31 days.
- No off-street parking is required if the unit is proposed within Transit Priority Area (TPA).
- For parcels outside of a TPA, one off-street parking space per dwelling unit is required for the third and fourth units (of any kind) constructed on the initial (unsubdivided) lot.
- One off-street parking space per dwelling unit is required within the Beach Impact Area of the Parking Overlay Zone unless the applicant can demonstrate to the satisfaction of the City Manager that there is access to a car share or other shared vehicle within one block of the premises.
- No setback is required for a conversion of an existing structure to a new dwelling unit;
- A dwelling unit constructed in the same location or within the building envelope as an existing structure may observe the same setbacks;
- Newly constructed dwelling units must comply with street and front setbacks in the underlying zone;
- Newly constructed one-story dwelling units with a 16-feet height or less may abut the interior side or rear property line;
- Newly constructed dwelling units exceeding 16-feet in height shall have a four-foot interior or rear setback if abutting a residential zone or a premise developed with exclusively residential uses.
Restrictions on Urban Lot Splits
In addition to the restrictions above, Urban Lot Split provisions may not be used in the following circumstances:
- The lot is not located in a single-family zone;
- The lot was established through a prior Urban Lot Split; or
- The recorded owner or any person acting with the recorded owner has previously subdivided an adjacent lot.
Parcels created through urban lot splits must comply with all the following:
- The two lots shall be approximately equal in size, with either lot not being smaller than 40 percent of the lot area of the original lot;
- The newly created lots shall not be smaller than 1,200 square feet;
- Any lots created shall be split in a manner that complies with the floor area ratio (FAR), street frontage, driveway width requirements and other standards in the underlying zone, whenever feasible:
- Developments that do not comply with street frontage and driveway width requirements of the base zone shall record an access easement on the lot.
Any rental unit created through an urban lot split shall not be rented for less than 31 days. In addition, only residential uses are permitted on a lot created by an urban lot split.
Number of Dwelling Units
The regulations allow no more than two MDUDs, whether existing or new, on a lot. Under certain circumstances, an applicant may also use these regulations in conjunction with the Accessory Dwelling Unit regulations. However, under no circumstances shall the total number of dwelling units across the two lots result in more than four units.
No Urban Lot Split: A property would allow up to two MDUDunits, subject to applicable regulations, and would allow up to two ADUs orJADUs; under no circumstances shall the total number of dwelling units resultin more than four units. Constructing accessory units in this manner mayrestrict future development.
Urban Lot Split: If the project proposes a lot split usingthe ULS provisions and construction of MDUD units, then no ADUs/JADUs would bepermitted. The project may propose up to two MDUDs on each lot resulting fromthe subdivision for a total of no more than four on the initial (unsubdivided)lot.
How to Apply
Applications for multi-family dwellings are being accepted in paperless digital formats:
- Digital Application Portal can be navigated here: Development Services Application Portal
- For new Permit Applications, request “Building Permit.”
- For changes to an existing issued permit (under construction), request “Construction Change to a Building Permit.”