Appraising 2 ADUs on one lot

[Imladaris]

Anybody come across this new thing on the menu? Subject to completion per plans.

 

[RCA]

Anybody come across this new thing on the menu? Subject to completion per plans.

Per Grok:

"Yes, several cities in California permit the construction of two accessory dwelling units (ADUs) on a single lot, particularly under specific conditions such as multifamily zoning, existing multifamily developments, or local ordinances that align with or exceed state guidelines. California state law (e.g., Government Code Section 65852.2) generally allows up to two detached ADUs on lots with an existing or proposed multifamily dwelling, and local jurisdictions may extend similar provisions to single-family lots in certain cases. Below is a summary of notable examples based on current regulations as of October 2025.

Key Examples of Cities Allowing Two ADUs on One Lot​

City	Conditions for Two ADUs	Relevant Notes/Source
San Diego	Permitted on multifamily-zoned lots, even if only a single-family residence currently exists. Up to two detached ADUs allowed.	Aligns with state law and local code updates; supports income-generating opportunities on underutilized zoning.
Del Mar	Allowed on lots with existing multiple dwelling unit developments; up to two detached ADUs per lot, subject to coastal resource protections.	Coastal Development Permit may require attachment to primary units in some designs to preserve access and resources.
Berkeley	Up to two ADUs on single-family lots, including one detached (e.g., garage conversion) and one backyard unit.	Enabled by state legislation like AB 68; designs can include flexible expansions for bedrooms.
Loomis	Up to three total dwellings per residential-zoned parcel: one primary, one ADU, and one Junior ADU (JADU).	Effectively allows two secondary units; visit local ADU building page for detailed standards.
Los Angeles	Up to two ADUs on single-family lots via Senate Bill 9 (SB 9), which enables two primary units plus two ADUs and two JADUs.	Applies to most residentially zoned lots; additional provisions under AB 1033 for separate ADU sales.

Additional Considerations​

• Statewide Context: For single-family lots, standard provisions limit developments to one ADU and one JADU unless local rules or tools like SB 9 provide exceptions. Multifamily lots consistently allow at least two detached ADUs statewide, with some cities (e.g., Santa Ana) permitting up to eight detached ADUs but capping at the number of primary units.
• Variations: Regulations can depend on lot size, zoning, setbacks (e.g., 4 feet minimum), height limits (typically 16 feet), and utility connections. Senate Bill 1211 (effective 2025) further expands multifamily ADU opportunities.
• Recommendations: Consult the local planning department or the California Department of Housing and Community Development (HCD) ADU handbook for site-specific verification, as ordinances evolve and may include pre-approved plans or fee waivers.

This framework supports California's housing goals by promoting density while respecting local contexts. If you provide a specific city or lot details, further tailored analysis is available."

 

[Surf Cat]

Anybody come across this new thing on the menu? Subject to completion per plans.

This "new thing" you're talking about.... can you give us a little more info? A little sparse on the details there.

Are you doing a subject to plans and specs in its entirety for the main dwelling and two ADUs? Just for the two ADUs? What's the H&BU for the site? Is there a trend to construct ADUs in the market area? If not, do you have duplexes and triplexes to hang your hat on?

Describe whatcha got going and you'll get some suggestions.

 

[sputnam]

In appraising, there can't be an ADU unless there is a main dwelling. It's in the definition of ADU. If you mean two tiny houses on one site... that's a two family property which might, or might not, be allowed in a particular zoning jurisdiction.

 

[Jerry Bone Jr]

Anybody come across this new thing on the menu? Subject to completion per plans.

H&BU - Original house plus 2 ADUs = convert to condominium, sell individually.

 

[Imladaris]

Are you doing a subject to plans and specs in its entirety for the main dwelling and two ADUs? Just for the two ADUs? What's the H&BU for the site? Is there a trend to construct ADUs in the market area? If not, do you have duplexes and triplexes to hang your hat on?

Precisely that.

Main house is going to be updated but the rear of the lot will have two new ADUs in the back.

My thinking was leaning on to 2plex and 3plexes because the ADU construction is so new. This will be the first in the immediate neighborhood. Extending out there are homes with a single ADU but not two.

 

[Sandra Koutsopoulos]

You may have a knotty problem there. What's the zoning? Unless local zoning says otherwise, you can have 1 main house and one smaller house with SFR zoning. 2 ADUs mostly not permitted. Maybe guesthouse/poolhouse/playhouse/treehouse/doghouse....

Sometimes zoning even says how many non-related ppl can occupy. I question whether they have permits for 3 virtual SFRs. Maybe check with zoning and see what THEY are calling that; you'll find out then if it is even permitted, and what they're calling it.