Alameda County Rent Control: 4% Cap, Just Cause & Exemptions

Rent control in Alameda County applies only to the county’s unincorporated areas, where a local ordinance caps annual rent increases at 4% and requires landlords to have a just cause reason to end a tenancy. If your rental sits inside a city like Oakland, Berkeley, Hayward, or Alameda, that city runs its own separate program and its rules govern instead.

Who the County Rules Cover

The county’s Rent Stabilization Ordinance and its just cause eviction ordinance apply to rentals in the unincorporated communities of Ashland, Castlewood, Castro Valley, Cherryland, Fairview, Happy Valley, Hillcrest Knolls, San Lorenzo, and Sunol.¹ These places have no city government, so the county’s Housing and Community Development Department administers tenant protections directly.

Every incorporated city in the county operates its own housing program with its own rules, forms, and contacts. If you live within any city’s limits, the county ordinance does not apply to your unit. Before assuming coverage either way, confirm the property’s jurisdiction with the county assessor or HCD.

The 4% Annual Rent Cap

For units covered by Chapter 3.71 of the Alameda County General Ordinance Code, the annual permissible rent adjustment is a flat 4%.² The number does not move with inflation. Whatever the Consumer Price Index does in a given year, a covered unit’s ceiling stays at 4%.

California’s Tenant Protection Act (AB 1482) sits underneath as a statewide backstop. It allows increases of up to 5% plus the local CPI change, capped at 10% total over any 12-month period.³ For units the county ordinance covers, the stricter local 4% cap wins. AB 1482 becomes the operative limit only for units that are exempt from the local ordinance but still covered by the state law, which is common with newer buildings and certain single-family homes.

Under AB 1482 a landlord can split an annual increase into two hikes within a 12-month window as long as the total stays inside the cap.³ Units under the local ordinance do not get that flexibility.

Notice for a Rent Increase

A rent increase has to come in writing. Increases of 10% or less require at least 30 days’ notice before the new amount takes effect. Increases above 10% require 90 days.⁴ A text, an email, or a verbal announcement does not meet the requirement, and an increase delivered without proper written notice is not enforceable on the date claimed.

Just Cause Eviction Rules

The Board of Supervisors passed a just cause eviction ordinance on February 4, 2025, and it took effect on March 6, 2025.⁵ In covered rentals, a landlord cannot end a tenancy without stating one of the recognized grounds in the notice itself. The county tracks the categories used under state law: at-fault reasons based on tenant conduct, and no-fault reasons that arise from the landlord’s plans for the property.

At-Fault Grounds

At-fault reasons involve something the tenant did or failed to do:⁵

Nonpayment of rent after it is due
Material lease violation after written notice to cure
Maintaining a nuisance or committing waste on the property
Criminal activity on or directed at the property or its owner
Unauthorized subletting
Refusing lawful entry to the landlord
Using the premises for an illegal purpose
Refusing to sign a new lease with substantially similar terms
Giving notice to leave and then not vacating
Ending employment where housing was tied to that job

No-Fault Grounds

No-fault grounds allow termination even when the tenant has done nothing wrong, and they carry extra obligations:

Owner or close family move-in, meaning a spouse, domestic partner, child, grandchild, parent, or grandparent⁵
Permanent withdrawal of the property from the rental market, a right the state’s Ellis Act protects⁶
Compliance with a government order requiring the unit to be vacated
Demolition or substantial remodel

Every eviction notice has to state the specific cause. For a no-fault notice, it must also explain the tenant’s right to relocation assistance and state the dollar amount.⁷ A notice missing that information is defective, and the tenant can raise the deficiency as a defense if the case reaches court.

Relocation Payments for No-Fault Evictions

A no-fault eviction entitles the tenant household to the greater of three months of current rent or three months of the HUD Fair Market Rent for the unit size in the Oakland-Fremont-Alameda County area.⁸ The landlord can waive the final month’s rent in writing and credit that against the total, but the remaining balance is still owed.

The total relocation obligation is capped at $28,000 per household. If a single month of current rent already exceeds $28,000, the landlord must still pay that one month.⁸

Some households qualify for one additional month on top of the base amount. Eligibility applies if the household includes at least one child under 18, a disabled person, an elderly tenant, or someone who qualifies as lower income under California Health and Safety Code Section 50079.5. The tenant has to give the landlord written notice with documentation of the qualifying condition to receive the extra payment.⁸

Substantial remodel evictions carry one extra protection. The displaced tenant has a right of first refusal to return once the work is done, with the same lease terms and the rent that was in place at move-out.⁵

Which Units Are Exempt

Not every rental in unincorporated Alameda County gets the full protection package. Exemptions come from two directions: the state Costa-Hawkins Rental Housing Act, which limits what local rent control can reach, and AB 1482’s own carve-outs.

Costa-Hawkins: Out of the Local 4% Cap

Costa-Hawkins blocks local rent control on any unit that received a certificate of occupancy after February 1, 1995. Newer buildings sit outside the county’s 4% cap, though AB 1482’s statewide formula still applies to most of them. Costa-Hawkins also carves out single-family homes, condominiums, and any unit that can be sold separately from others in the building.⁹

AB 1482: Out of the Statewide Protections

Some units are exempt from both the statewide rent cap and the statewide just cause rules:³

Housing with a certificate of occupancy issued in the last 15 years, on a rolling basis
Single-family homes and condos, but only if the owner is not a corporation, REIT, or an LLC with any corporate member, and only if the landlord has delivered the required written exemption notice to the tenant
Owner-occupied duplexes where the owner lives in one unit as a principal residence and neither unit is an ADU
Deed-restricted affordable housing for very low, low, or moderate income households
Dormitories owned and operated by schools or higher education institutions

The single-family exemption trips up plenty of landlords. If the owner is an LLC or corporate entity, or if the written exemption notice was never delivered to the tenant, the exemption fails and the unit is fully covered by both the statewide cap and the just cause rules. Federally subsidized housing where rent is tied to tenant income runs under its own federal rules, and hotels, motels, and other transient lodging are outside these protections entirely.¹⁰

Challenging an Increase or Overcharge

If a rent adjustment on a covered unit does not match the ordinance, either the tenant or the landlord can file a petition with the county’s Rent Review Officer, a position housed within HCD. The petition asks for an upward or downward adjustment to the maximum allowable rent.² Before filing, gather the current rent, the proposed new rent, the effective date, the unit address, and a copy of the landlord’s written notice.

A tenant who believes the landlord has charged rent above the legal maximum can go a different route and file an administrative complaint. The county must resolve those complaints within 120 days.²

Penalties for Overcharging and Improper Evictions

A landlord who charges more than the maximum allowable rent is liable for the overcharge plus a penalty of up to $500 per violation, and the tenant can also recover the costs of pursuing the administrative complaint.² The tenant has to prove entitlement to the extra penalty.

On the eviction side, a tenant who receives a notice without valid just cause, or a no-fault notice that fails to include the required relocation information, can raise those problems as a defense in an unlawful detainer case. If the court agrees, the case can be dismissed, and unpaid relocation assistance can be recovered as part of the defense. Current ordinance text, forms, and Rent Review Officer contact information are available through the county’s Housing and Community Development Department at achcd.org.

1
Alameda County. Cities
2
Alameda County. Alameda County General Ordinance Code Chapter 3.71 – Rent Stabilization
3
California Legislative Information. California Civil Code 1947.12
4
California Department of Justice. Know Your Rights as a California Tenant
5
Housing & Community Development Department. Just Cause for Eviction Ordinance Passed
6
California Legislative Information. California Government Code 7060
7
Housing & Community Development Department. Tenant Protections
8
Alameda County. Revised Second Reading – Continued From 02/27/2024
9
California Legislative Information. Costa-Hawkins Rental Housing Act
10
California Legislative Information. California Civil Code 1946.2