ADU Development
In 2025, California's ADU laws, including AB 2533, SB 1211, and SB 1077, aim to streamline ADU development, legalize unpermitted units, expand ADUs on multi-family properties, and provide guidance for coastal ADUs, with some restrictions on local regulations.
Here's a breakdown of the key changes:
1. Legalizing Unpermitted ADUs (AB 2533)
Local agencies must allow unpermitted ADUs built before January 1, 2020, to be legalized if they meet health and safety codes.
Owners can seek private contractor inspections to estimate costs for upgrading to meet code.
Local agencies cannot charge impact fees for unpermitted ADUs unless they require new utility connections.
2. Expanding ADUs on Multi-Family Properties (SB 1211):
Allows one detached ADU per existing residential unit, up to eight ADUs per property.
Designed to increase housing supply on existing multi-family lots.
3. Streamlined ADU Development Process (AB 68)
Cities must approve one ADU (up to 1,200 sq ft) and one Junior ADU (JADU, up to 500 sq ft) per single-family lot.
Applications must be approved within 60 days, with no hearings or discretionary reviews.
No owner-occupancy requirement for ADUs permitted by 2025.
4. Coastal ADU Guidance (SB 1077)
The California Coastal Commission and HCD will issue guidance for ADUs and JADUs in coastal areas.
The goal is to help local governments simplify coastal ADU permitting.
5. Additional Key Changes
No Owner-Occupancy Requirement:
For ADUs approved by 2025, property owners are not required to live on-site.Impact Fee Limits:
No impact fees for ADUs under 750 sq ft.
Proportional fees may apply to larger units.
HOA Restrictions Eased:
HOAs must allow ADUs, though they can regulate design and aesthetics.
Condo Conversions (AB 1033):
ADUs can now be sold separately as condominiums, providing new opportunities for homeowners, developers, and investors.
The key highlights of the new state ADU law are summarized below.
Reduced Costs and Burdens for Developing ADUs
ADU applications must be approved within 60 days, without a hearing or discretionary review
For ADUs permitted by 2025, cities/counties cannot require the owner to live at the property
No impact fees are required for ADUs under 750 sqft; proportional fees apply to larger ADUs
An ADU can be developed at the same time as a primary dwelling, with no additional hearing
A city/county must delay code enforcement on an unpermitted ADU to allow it to be legalized
Single-family HOAs must allow development of ADUs, subject to reasonable standards
Single-family homeowners can also develop JADUs—units under 500 sqft within a residence
ADUs Subject to Automatic Approval — No Local Limits
Cities/counties must permit certain categories of ADUs without applying any local development standards, if proposed on a single-family lot. ADUs eligible for this automatic approval include:
• An ADU or JADU converted from existing space in the home or another structure (e.g., a garage), so long as the ADU has exterior access and setbacks sufficient for fire safety
• A new detached ADU under 800 sqft in size, 16 feet in height, with 4-foot side/rear setbacks
• Multiple of the above options to create one internal JADU and an internal or detached ADU
ADUs Subject to Automatic Approval — No Local Limits
Cities/counties must permit certain categories of ADUs without applying any local development standards, if proposed on a single-family lot. ADUs eligible for this automatic approval include:
• An ADU or JADU converted from existing space in the home or another structure (e.g., a garage), so long as the ADU has exterior access and setbacks sufficient for fire safety
• A new detached ADU under 800 sqft in size, 16 feet in height, with 4-foot side/rear setbacks
• Multiple of the above options to create one internal JADU and an internal or detached ADU
ADUs Subject to Ministerial Approval — Minimal Local Limits
Cities/counties must generally approve attached or detached ADUs under 1,200 sqft unless they adopt local development standards. If adopted, local standards have the following limitations:
• No minimum lot size requirement
• No maximum unit size limit less than 1,000 sqft for a two-bedroom ADU
• No requirement for replacement parking when a parking garage is converted into an ADU
• No required parking for an ADU created through the conversion of existing space or located within a half-mile walking distance of a bus stop or other public transit
• No height limit under 16 feet or side/rear setback requirements over 4 feet
• No setback requirements for conversions/replacements of existing legal structures
• Design standards must be objective and are assessed by staff, not elected officials
• FAR and similar restrictions must be relaxed to allow development of an 800 sqft ADU
Adding Units to Multifamily Properties
The following types of residential units can be added to multifamily buildings, with no local limits:
• New units within the existing non-living space of a building (storage rooms, basements, garages, etc.), with one new internal unit allowed for every four existing units
• Two new detached homes, with 4-foot side/rear setbacks, up to 16 feet in height
