Cities | Hayward

Hayward Multiplex Rules 2026: Triplexes, ADUs, SB 9, Rent Rules and Fees

Hayward, in Alameda County, publishes its Municipal Code on Municode. Chapter 10 holds zoning, parking, subdivisions, park and traffic fees, affordable housing and the two form-based codes for Mission Boulevard and Downtown; Chapter 12 holds rent stabilization and tenant relocation. This page sums up the routes to two, three, four or more homes on a Hayward lot, what each allows, and where City documents and state law differ. The code was read in Supplement 28 Update 1, which carries ordinances through No. 26-06 of May 5, 2026. The seven guide pages below cover each topic in depth.

Hayward Guide Pages

Start With State Law

Four state laws set the floor Hayward must allow. SB 9 (2021) allows two main homes on a lot in a single-family zone, a split into two lots, or both, approved by staff with no hearing. ADU law sets the accessory dwelling units (ADUs), which are second homes on a lot, and junior ADUs a city must allow; a junior ADU is a unit of 500 square feet or less inside the house. SB 684 and SB 1123 allow maps of up to 10 lots with 10 homes. SB 79 allows taller and denser projects near rail stations in an "urban transit county."

HCD's SB 79 advisory says the upzoning rules "will take effect on July 1, 2026, in Alameda" County and six others, and its rail table lists BART stations, other than two eBART stops, as heavy rail. The Hayward code names two BART stations, Hayward and South Hayward. So SB 79 reaches parts of Hayward now, along with SB 9, ADU law, SB 684 and the state density bonus.

Hayward has a City Charter; Section 200 gives the City power "to make and enforce all laws and regulations in respect to municipal affairs." The SB 9 statutes apply to every city "whether general law or chartered." Hayward relies on state law with little local text: Section 10-1.2741 only "provides reference to the regulations for Accessory Dwelling Units" in the Government Code, and the use table permits a "Two-Unit Development" in RL "As provided in Government Code Sections 66411.7 and 65852.21." The City's details are in its ADU and SB 9 checklists.

Hayward in Numbers

The US Census Bureau's Vintage 2025 city file estimates 157,113 people in the City of Hayward on July 1, 2025, down from a 2020 estimates base of 162,900. In that file Hayward is the 36th largest city in California, after Salinas (159,134) and ahead of Sunnyvale (156,577). Alameda County has 1,636,630 people in the same file.

Most housing decisions in Hayward are made by staff. The Planning Director has "final approval authority" for site plan reviews, administrative use permits and administrative variances, and for tentative parcel maps that meet the code. The Planning Commission decides conditional use permits referred to it, most variances and tentative tract maps, and hears appeals of Director decisions. The City Council decides zone changes, General Plan amendments and appeals of Commission decisions. The permits and fees page has the deadlines.

The Routes to More Homes Compared

Sources: Hayward Municipal Code 10-1.202, 10-1.209 and 10-1.802; City ADU and SB 9 checklists; Government Code 66411.7, 66499.41 and 65912.157.

Zones That Allow Homes

Hayward has four residential districts. RL, the Low Density Residential District, is the old single-family zone; Section 10-1.201 says the RS district "shall now be known as" RL and that RL "is suitable for detached residential units, duplexes, triplexes." RM allows "a mingling of different housing types and densities," and RH is for "multi-unit buildings." RNP covers hill land where the slope and natural features come first. Homes are also allowed in the RO, CO, CN-R, CN, CG and CB commercial districts, in the Sustainable Mixed Use district at 25.0 to 55.0 homes per acre, and in the Mission Boulevard and Downtown zones.

The zoning district sets the building type, and the General Plan sets the count. Section 10-1.204(e) says "Allowable density shall be determined by the applicable General Plan land use designation and net acreage." The General Plan ranges are 4.3 to 8.7 homes per net acre for Low Density land, 8.7 to 17.4 for Medium Density and 17.4 to 34.8 for High Density. By VanPlex arithmetic at 43,560 square feet per acre, a Low Density lot needs 10,014 square feet for a duplex and 15,021 for a triplex. See the zoning districts page.

House Lots: ADUs and SB 9

The City ADU checklist allows a new detached ADU of up to 1,200 square feet of interior livable space, 16 feet tall, or 18 feet within one-half mile of a major transit stop, with 4 foot side and rear setbacks. The checklist limits a house lot to one ADU and one junior ADU, while Government Code 66323 requires approval of a converted ADU and junior ADU plus a detached ADU of up to 800 square feet; the statute controls. See the ADUs and SB 9 page.

An SB 9 two-unit project puts two main homes on an RL lot, with 4 foot side and rear setbacks, a 30 foot height limit and 50 facade design points. Housing "occupied by a tenant in the last three years" is excluded. An urban lot split gives two lots of at least 1,200 square feet, and the owner signs an affidavit to live in one home for three years. The lots and subdivisions page covers maps and SB 684.

Three or More Homes

A triplex is permitted in RL, RM and RH, and a building of four or more homes in RM and RH, up to 50 feet in RM and 60 feet in RH. Every project of "two (2) or more Dwelling Units or lots" falls under the affordable housing ordinance: 6 percent of a rental project's homes built as affordable, or an in-lieu fee, which is $23.30 per square foot of habitable space for most types and half that for projects under 10 homes. Along Mission Boulevard, density runs to 100 homes per acre in the TOD Overlay 1 near BART, with no minimum parking. See the three or more homes page.

Parking, Setbacks and Height

A detached house of up to 3,000 gross square feet needs two spaces "within an enclosed garage," and a larger one three. Each home in a duplex or larger building needs 1.0 covered space plus 0.50 to 1.10 uncovered by bedroom count, and minimums are not enforced within one-half mile of a major transit stop. RL needs a 15 foot front yard, or 20 feet to an attached garage, and allows 30 feet and two stories. The Hayward Hills, east of Mission Boulevard and south of D Street, add stepped design rules on slopes of 15 percent or more. See the parking, setbacks and height page.

Rent Stabilization and Tenants

Hayward caps rent increases on covered units at five percent once every twelve months. Units in a building first given a certificate of occupancy after July 1, 1979 are outside the cap, so new homes start outside it. Just cause rules cover all rentals. Ending a tenancy to demolish requires City permits first and relocation pay equal to one month of rent, and Section 10-1.2737 requires a project to replace every home it demolishes. See the rent and tenant rules page.

Fees

New Hayward homes pay a park impact fee by bedroom count, $10,699 for a two-bedroom home in FY 2026-27, a traffic impact fee of $3,922 per single-family home or townhome, a sewer connection charge of $14,559 per home from September 1, 2026, and a water facilities fee by meter size. Park and traffic fees are due before final inspection or occupancy. Planning applications start with deposits billed at $249 an hour. See the permits and fees page.

Where City Documents and State Law Differ

The guide pages flag each gap where it arises. The main ones: the ADU checklist limits a house lot to one ADU and one junior ADU, fewer than Government Code 66323 requires; the checklist and fee schedule charge park fees on an ADU of exactly 750 square feet, which Government Code 66311.5 bars; the City SB 9 page labels SB 9 "Requires Planning Commission Approval" and quotes three to five months, while the statutes require ministerial review and a 60 day decision; Section 10-1.2741 still cites Government Code 65852.2 and 65852.22, which are no longer in the code; and Section 12-2.03(d) calls Section 66300.6 part of the Civil Code when it is in the Government Code. In each case the statute controls. The General Plan names only detached homes for Low Density land, while the zoning code permits duplexes and triplexes in RL; the 2023 staff report says the zoning code decides the building type and the General Plan the count.

Limits of This Guide

Every rule on these pages is the Municipal Code text in Supplement 28 Update 1, read on October 9, 2026, plus the City pages, checklists, fee schedule, General Plan and Council records named on each page. A search of Council matter titles since May 2026 found no new zoning ordinance. On October 6, 2026 the City Council passed an item amending the General Plan land use element to carry out programs of the Downtown Specific Plan; these pages do not cover that change. The zoning map, the General Plan map and the BART stop list for SB 79 were not read for any single lot. Confirm the rules for your lot with the Planning Division before you budget or design.

Where to Go Next

Related on VanPlex: the California ADU law page, the California rent and tenant rules page and the duplex to fourplex guide.

Frequently Asked Questions

Official sources (checked October 2026)