California ADU 30-Day Rental Rule: 31-Night Minimum

What the California ADU 30-day rental rule says

Government Code Section 66323(e) reads, in its operative sentence, that a local agency shall require that a rental of the accessory dwelling unit created pursuant to this section be for a term longer than 30 days. Subdivision (a) of the same section lists the unit types the local agency must ministerially approve: one accessory dwelling unit and one junior accessory dwelling unit per lot with a proposed or existing single-family dwelling under paragraph (1), one detached new construction accessory dwelling unit with four-foot side and rear yard setbacks under paragraph (2), conversions of non-livable space within an existing multifamily dwelling under paragraph (3), and detached accessory dwelling units on a lot with an existing or proposed multifamily dwelling under paragraph (4).

Subdivision (e) attaches the rental term to every unit the local agency must ministerially approve under subdivision (a). The same section sets the unit count, and subdivision (e) sets the rental term; the two subdivisions work together. Section 66333(g) carries the same requirement onto a junior accessory dwelling unit, requiring a junior accessory dwelling unit ordinance to require that a rental of a junior accessory dwelling unit be for a term longer than 30 days. Section 66333(g) was added by Assembly Bill 1154 of the 2025 statute, chaptered October 10, 2025 and effective January 1, 2026, and Section 66323(e) was amended by Senate Bill 543 of the 2025 statute, chaptered in 2025 and effective January 1, 2026. Before that date, the equivalent rental term was written as a local option under the older framework rather than as a state mandate.

The text matters because the words a term longer than 30 days are not the same as 30 days or longer. A letting of exactly 30 nights satisfies a 30 days or longer test, because the boundary is inclusive. A letting of exactly 30 nights does not satisfy a term longer than 30 days test, because the boundary is exclusive. On the face of Section 66323(e) and Section 66333(g), a 30 night stay falls one night short, and the shortest compliant stay is 31 nights.

• Section 66323(e): a local agency shall require that a rental of the accessory dwelling unit be for a term longer than 30 days for every unit type listed in subdivision (a).
• Section 66333(g): a junior accessory dwelling unit ordinance shall require that a rental of a junior accessory dwelling unit be for a term longer than 30 days.
• Section 66315, the older permissive provision: a local agency may require that the property be used for rentals of terms 30 days or longer, where the local agency has adopted its own ADU ordinance and has not used the Section 66323 ministerial pathway.

Why the minimum is 31 nights, not 30

Two California statutes are written differently, and the difference is one night. Section 66315, the older permissive provision, lets a local agency require rentals of terms 30 days or longer. A 30 night stay satisfies 30 days or longer because the boundary is inclusive. Section 66323(e) and Section 66333(g), the operative rules for the 2026 framework, require a term longer than 30 days. A 30 night stay does not satisfy longer than 30 days because the boundary is exclusive. The shortest compliant stay on a unit approved under Section 66323 or on a JADU subject to Section 66333(g) is 31 nights.

A platform or lease template that defaults to a 30 day minimum will fall one night short on the Section 66323 or Section 66333(g) pathway. The simplest fix is to set the platform minimum stay to 31 nights, write the lease template with a 31 day term, and confirm with the city planning counter how the agency counts a term, because the same 30 day period can read as 30 nights on a platform calendar and as 30 days in a lease depending on whether the day of entry and the day of exit are both counted. The two counts can differ by one at the margin, and the count that matters is the one the city uses.

Section 66325(a) preempts a local ordinance that conflicts with Article 2, except that local agencies may adopt less restrictive requirements. A city ordinance that tries to set a 30 day minimum on a Section 66323 unit is more restrictive than a term longer than 30 days on its face, and that ordinance is preempted. A city ordinance that adopts no minimum term at all is also more restrictive than Section 66323(e), because Section 66323(e) is a mandate, not a permission, and the mandate is binding without any local adoption. A city that wanted to allow a 30 night stay on a Section 66323 unit would have to relax its own ADU ordinance below the state floor, which is the opposite of the way the preemption rule works.

What the rule does not cover

Section 66323(e) attaches the rental term to the unit types listed in subdivision (a) of Section 66323, not to every accessory dwelling unit the city might approve. A city that approves an ADU under its own ADU ordinance, outside the Section 66323 ministerial pathway, is governed by Section 66315 rather than Section 66323(e). Section 66315 preserves the local power to require rentals of terms 30 days or longer, but it does not require the city to impose a minimum term, and a city that does not exercise that power leaves the door open to a 30 night stay. The 31 night floor binds on a Section 66323 unit; it does not bind on a unit the city approved under its own ordinance without using the Section 66323 pathway.

The same boundary appears for a junior accessory dwelling unit. Section 66333(g) binds through the local JADU ordinance, which Article 3 requires the city to adopt. A city that has not adopted a JADU ordinance at all is in a separate state of non-compliance with Article 3 and is bound by Section 66339.5(a), which carries the same preemption rule for Article 3 that Section 66325(a) carries for Article 2 and was added by Senate Bill 543 of the 2025 statute, effective January 1, 2026. The practical result is that on a JADU the 31 night floor is also state law, but the path by which it becomes binding runs through the JADU ordinance rather than the approval pathway used for the ADU.

Section 66323(e) does not address owner occupancy. A local agency may not impose an owner-occupancy requirement on a standard accessory dwelling unit under Section 66315, added to the Government Code by Senate Bill 477 of 2024, effective March 25, 2024, and the same owner-occupancy prohibition, carried into Section 66314 of the Government Code by Assembly Bill 976 of 2023, applies to a unit approved under Section 66323(e). Owner occupancy for a JADU is governed separately by Section 66333(b) as amended by AB 1154, and it runs on whether the JADU shares sanitation facilities with the primary dwelling. The 31 night rental term and the owner occupancy question are two different questions, and the answer to one does not change the answer to the other.

How the rule interacts with the rest of state ADU law

Section 66325(a) reads that Article 2 supersedes a conflicting local ordinance, except that a local agency may adopt less restrictive requirements. Section 66323 is part of Article 2. A local ordinance that tries to set a shorter minimum rental term than the 31 night floor set by Section 66323(e) is more restrictive, not less restrictive, and is preempted. A local ordinance that allows a shorter minimum term, such as a 1 night stay, is less restrictive on its face but conflicts with the state mandate that a local agency shall require a term longer than 30 days; the conflict is with the mandate itself, not with the floor, and the city cannot satisfy the mandate by allowing less.

Section 66323(b) reinforces the rule at the unit level: a local agency shall not impose any objective development or design standard that is not authorized by Section 66323 upon any unit that meets the requirements of any of paragraphs (1) to (4), inclusive, of subdivision (a). The rental term set by Section 66323(e) is one of the few state-level rules of that kind, and a local agency that tries to substitute a different rental term for the Section 66323(e) term runs into the preemption rule in Section 66325(a) as well as the design standard bar in subdivision (b) of Section 66323. The two provisions read together leave the rental term set by state law on a Section 66323 unit, with the local agency preempted from substituting its own shorter or longer minimum.

Section 66323(c) carries the rule into the application intake: a local agency shall not require, as a condition for ministerial approval of a permit application for the creation of an accessory dwelling unit or junior accessory dwelling unit, the correction of nonconforming zoning conditions. A nonconforming primary dwelling or a nonconforming lot cannot be used to deny the ADU application, even when the ADU itself would meet state law. The rental term rule is not a condition of approval in the sense of Section 66323(c); the rule attaches to the unit after approval, in the rental phase, rather than to the application. The intake rule and the rental rule are separate protections, and both apply to a Section 66323 unit.

How L Square confirms the rental term on a real Orange County or Los Angeles County lot

L Square Design & Build's site review for a 31 night rental term starts with the approval record, not the local ordinance. The ADU's building permit and the approval letter are pulled, and the planner on the lot is asked which statutory pathway the unit was approved under. A unit approved ministerially under Section 66323(a)(1) through (a)(4) is bound by the 31 night floor in Section 66323(e). A unit approved under the local ADU ordinance outside the Section 66323 pathway is governed by Section 66315 and the 30 day or longer permissive text that the local ordinance adopted.

L Square's published 2026 model lineup runs from the 600 sq ft two bedroom Model 600 at $180,000, to the 800 sq ft Models 800A and 800B at $240,000 each, to the 1,000 sq ft Models 1000A and 1000B at $295,000 each, up to the 1,200 sq ft Model 1200 at $354,000. The 600 and 800 sq ft models fit Section 66323(a)(2) as the state-protected detached ADU on a single-family lot and are bound by the 31 night floor in Section 66323(e). The 1,000 and 1,200 sq ft models use Section 66314(d)(5) as a larger size for the same single detached unit on the lot, and the same rental term rule applies because the approval pathway is the same Section 66323 pathway.

A 700 sq ft detached ADU with a vaulted ceiling built by L Square in Pasadena is documented on the project walkthrough page, with the finished great room, kitchen, bath, and bedroom shown. That unit sits within the 800 sq ft Section 66323(a)(2) state-protected cap and the four-foot side and rear setbacks, so it was permitted through the standard ministerial process under State ADU Law and is bound by the 31 night floor in Section 66323(e). A completed 1,188 sq ft two-story ADU in Rosemead is documented on the second project walkthrough page, an example of how L Square works within the Section 66314(d)(5) 1,200 sq ft size ceiling on the same lot as the primary dwelling and within the Section 66323(e) rental term rule for the ADU approval pathway.

For homeowners comparing the rental term across California, the right questions for the local agency are: (1) was the unit approved ministerially under Section 66323 or under the local ADU ordinance, (2) does the local JADU ordinance include the Section 66333(g) language, and (3) is the lease template set to a 31 night minimum and not a 30 night minimum. Those three answers drive the rental term rule. L Square Design & Build can be reached at (949) 374-7980 to discuss a specific lot in Orange County or Los Angeles County.