Cities | Oakland and Berkeley

Oakland and Berkeley Multiplex Rules 2026

Oakland and Berkeley sit next to each other in Alameda County, and both allow more primary homes on one house lot than the two that SB 9 (2021) requires. Berkeley's Middle Housing rules, in effect since November 1, 2025, set density by units per acre and approve small projects in 30 days. Oakland's RD zone, amended in 2023, sets unit counts by lot size. This page compares the two and shows where SB 9 and the other state laws still matter. For Berkeley's place in the wider history of zoning reform, see VanPlex's Berkeley policy page.

Start With State Law

Both cities must allow what state law requires. SB 9 allows two primary homes on a lot in a single-family zone, a split into two lots, or both, with staff approval and no hearing. ADU law sets the accessory dwelling units (ADUs), second smaller homes on a lot, that every city must approve. SB 684 and SB 1123 allow up to 10 lots with 10 homes on a multifamily-zoned lot or a vacant single-family lot of up to 1.5 acres.

Alameda County is one of the seven counties where SB 79 took effect July 1, 2026. Lots within a half mile of a qualifying rail or bus stop can hold buildings of five or more homes at 30 or more units per acre. Three 2026 state laws start January 1, 2027 in both cities: AB 956 (two detached ADUs per single-family lot), AB 2601 (SB 9 homes and lot splits processed together) and AB 1751 (for-sale townhome projects). In each city, compare the local rules below with these state options and use whichever allows the project you want.

The Two Cities in Numbers

The US Census Bureau estimates 440,838 people in Oakland and 121,911 in Berkeley on July 1, 2025. The California Department of Finance's E-5 estimate for January 1, 2026 counts 429,591 people and 192,719 housing units in Oakland, with 32,987 in buildings of two to four units. For Berkeley it counts 127,654 people and 55,521 housing units, with 10,133 in two- to four-unit buildings. The two agencies use different dates and methods.

Berkeley R-1 and Oakland RD Side by Side

Sources: Berkeley Ordinance 7,978-N.S., Berkeley Middle Housing page and Oakland Planning Code Chapter 17.15.

Berkeley: Ordinance 7,978-N.S.

Berkeley's City Council passed the "Middle Housing Zoning Amendments" to print at a special meeting on June 26, 2025. The vote was 9 to 0: "Ayes: Bartlett, Blackaby, Humbert, Kesarwani, Lunaparra, O'Keefe, Taplin, Tregub, and Ishii. Noes: None." The city says the rules were adopted in July 2025, and Section 52 of the ordinance sets the effective date: "The effective date of this Ordinance shall be November 1, 2025."

The ordinance rezoned "all parcels currently zoned R-1A to R-2," which removed the R-1A zone, and renamed R-1 "Residential Multi-Unit 1" and R-2 "Residential Multi-Unit 2." The city's Middle Housing page says "Middle Housing is permitted in areas zoned R-1, R-2, R-2A, and MU-R." The rules "do not apply to the high fire hazard areas in the Berkeley Hills."

The new R-1 standards (Table 23.202-2) replace a unit cap with a density range. The minimum is 10 units per acre and the maximum is 70. On a 5,000 square foot lot, 70 units per acre works out to 8 units (70 times 5,000, divided by 43,560 square feet in an acre, is 8.03). Height is "35 ft. or 3 stories," or 22 feet within 15 feet of the rear line, and the city says no permit can raise it. There is "No maximum" floor area ratio. Lot coverage is capped at 60 percent. Usable open space must be 150 square feet per 1,000 square feet of residential floor area. New lots must be at least 5,000 square feet, and buildings need 5 feet of separation.

On setbacks, the ordinance table shows 5 feet in front and 5 feet in the rear, with a footnote, and 4 feet on interior and street sides. The city page states the rule this way: "Front and rear setbacks must total at least 20 feet, with a minimum of five feet in the front and five feet in the rear." Design to the city page's 20-foot total and confirm with planning staff.

One rule limits large single homes. "The residential gross floor area of a single-family residential dwelling may be no larger than 50 percent of the lot area, or 2,500 square feet, whichever is greater," unless the owner gets an Administrative Use Permit. Small additions are simpler: an addition up to 10 percent of lot area or 200 square feet, whichever is less, needs only a Zoning Certificate.

Berkeley's 30-Day Approval

The city says "two- to six-unit 'middle housing' projects that meet development standards can get approval from the City in 30 days." The approval is a ministerial Middle Housing zoning certificate, meaning staff check the plans against the written standards with no hearing. "Approved applications cannot be appealed to the Zoning Adjustments Board or the City Council."

Notice still goes out. Within ten working days of an application, the city mails a courtesy notice to tenants and neighbors. The notice tells tenants how to reach a Rent Board Housing Counselor. "The applicant shall be responsible for the cost of materials, postage, and staff time necessary to process and mail notices." The notice rule does not apply in the Hillside Overlay Zone. Contact the Planning and Development Department at [email protected] or (510) 981-7410.

Oakland: The RD Zone

Oakland's RD Detached Unit Residential Zone is in Planning Code Chapter 17.15, amended by Ordinance 13763 on October 3, 2023. The code text read for this page is current through Ordinance 13868, enacted December 16, 2025. The zone's stated intent is "a mix of single-unit structures, small multi-unit buildings, and neighborhood businesses where appropriate."

Unit counts depend on lot area: "1-2 units on any legal lot; 3 units on minimum 3,000 sf. lots; 4 units on minimum 4,000 sf. lots." A "Two- to Four-Family Dwelling" is a permitted use. Floor area ratio and lot coverage limits apply only to one and two units, and the code lists the "Maximum Lot Coverage for 3 or More Units" as "N/A," so a triplex or fourplex has no coverage cap.

Other RD standards set the size and position of the building. Height is a 30-foot wall height, with 35 feet for a pitched roof on lots whose footprint slope is 20 percent or less. The front setback is 15 feet, or 5 feet where the slope from the street to the setback line exceeds 20 percent. Interior and street side setbacks are 4 feet on lots of 3,000 square feet or more. A lot must be at least 2,000 square feet, with 20 feet of width and 20 feet of frontage.

Design review may apply. Section 17.15.020 says most new buildings in the zone need design review approval, and the exemptions are in a separate section, 17.136.025. Ask Oakland planning staff whether your project is exempt before you finish drawings.

Where State Law Still Helps

SB 9 covers only lots in a single-family residential zone. HCD says lots in multifamily, commercial, agricultural or mixed-use zones "are not subject to SB 9 mandates even if they allow single-family residential uses as a permitted use." Oakland's RD zone now permits two- to four-family dwellings, and Berkeley renamed R-1 "Residential Multi-Unit 1." Ask planning staff in each city whether your zone still counts as single-family for SB 9 before you plan an SB 9 lot split.

ADU law applies in both cities whatever the answer. A new building of two or more attached homes counts as a "multifamily dwelling" for ADU law, according to HCD, so a city must allow up to two detached ADUs with a proposed triplex or fourplex. Once the building exists, the limit becomes up to eight detached ADUs, but no more than the number of existing units, plus ADUs in existing space that is not lived in, such as storage rooms and basements (at least one, and up to 25 percent of the units). ADUs of 750 square feet or less pay no impact fees.

Fire maps decide more than the Berkeley Hills rule. SB 9 and SB 684 both exclude very high fire hazard severity zones. HCD says a high fire hazard zone "is not a conclusive rationale to warrant restricting ADUs." The State Fire Marshal released 2025 recommended Local Responsibility Area fire hazard maps starting in February 2025, and each city must adopt the recommended zones by ordinance within 120 days of receiving them. The property tax and insurance page explains the fire zone rules.

Rent Rules and Loan Limits

The statewide rent cap in Civil Code 1947.12 uses the Consumer Price Index for the San Francisco-Oakland-Hayward area for Alameda County. Increases are limited to 5 percent plus that change, or 10 percent, whichever is lower, and homes with a certificate of occupancy from the previous 15 years are exempt. Local rules can be stricter; Berkeley's notice rule points tenants to its Rent Board. See the rent and tenant rules page.

The Federal Housing Finance Agency's 2026 conforming loan limits for Alameda County are $1,249,125 for one unit, $1,599,375 for two, $1,933,200 for three and $2,402,625 for four. The 2026 maximum Level I school fee is $5.38 per square foot of assessable space; ask each city for its local development fee schedule.

Where to Go Next

Related on VanPlex: Berkeley Middle Housing in the global zoning comparison and the duplex to fourplex guide.

Frequently Asked Questions

Official sources (checked October 2026)