The city recognizes the importance of affordable housing and an attractive, suitable living environment for all residents. The state legislature has declared that accessory dwelling units (ADUs) are a valuable form of housing in California. It is the intent of this chapter to permit ADUs, in conformance with state law, in designated zones subject to standards that will ensure the units contribute to a suitable living environment for people of all ages and economic levels, while preserving the integrity and character of residential neighborhoods in a manner consistent with the city's general plan.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

The following terms when used in this chapter will have the meanings provided in this section:

"Accessory dwelling unit" or "ADU" means a self-contained living unit located on the same parcel as a primary dwelling unit. An accessory dwelling unit also includes: (a) an efficiency unit, as defined in Health and Safety Code section 17958.1, and (b) a manufactured home, as defined in Health and Safety Code section 18007.

"Accessory structure" means a structure that is accessory and incidental to a dwelling located on the same lot.

"Attached ADU" means an ADU that:

1.

shares at least one common wall with the primary dwelling unit; and

2.

is not fully contained within the existing space of the primary dwelling unit.

"Detached ADU" means an ADU that does not share a common wall with the primary dwelling unit and is not an internal ADU.

"Internal ADU" means an ADU that is fully contained within the existing space of the primary dwelling unit or an accessory structure.

"Junior ADU" or "JADU" means an ADU that is no more than 500 square feet in size and contained entirely within a single-family residence.

"Public transit" means a location where the public may access buses and other forms of transportation that charge set fares, run on fixed routes, and are available to the public.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

A.

When Consistent With Standards.

1.

An ADU that complies with all standards in this chapter will be approved ministerially with an administrative permit. No discretionary review or public hearing is required.

2.

If a single-family or multi-family dwelling exists on the parcel upon which an ADU is proposed, the city will act on an application to create an ADU within 60 days from the date the city receives a completed application. If the applicant requests a delay in writing, the 60-day time period will be tolled for the period of the delay.

(a)

The city has acted on the application if it:

(1)

approves or denies the administrative permit for the ADU;

(2)

informs the applicant in writing that changes to the proposed project are necessary to comply with this chapter and provides a list of items that are defective or deficient with a description of how the application can be remedied; or

(3)

determines that the ADU does not qualify for ministerial approval.

3.

If the ADU application is submitted with a permit application to create a new single-family dwelling on the parcel, the city may delay acting on the ADU application until the city acts on the permit application for the new single-family dwelling.

B.

When Dependent on Separate Construction. When a proposed ADU is dependent on the construction of a new building or new portion of a building which is not a part of the ADU ("separate construction"), the city will either:

1.

Accept and begin processing the ADU application only after acting on an application for the proposed separate construction; or

2.

Upon written request from the applicant, review and act on the ADU together with the separate construction as part of a single application. In this case, the ADU is subject to the same review procedures and requirements as the separate construction, and may not be occupied until a certificate of occupancy is issued for the separate construction.

C.

Variance from Standards. No variance from any requirement of this chapter may be approved, nor will any application for such a variance be accepted for processing through administrative review of an ADU by the community development department. Should a variance from any requirement of this chapter be requested, review of the application by the planning commission will be required pursuant to Chapter 17.66 of this code.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

A.

ADUs are permitted on legal lots with an existing single-family residence or in conjunction with a proposed single-family residence in the city's residential zoning districts: R-A-10, R-A-15, R-A-20, R-A-E, RPD, and A.

B.

ADUs are also permitted on legal lots with an existing multi-family residence or in conjunction with a proposed multi-family residence in the Mixed Use Overlay District.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

A.

Single-Family Parcel.

1.

Except as provided in subsection (A)(2) below, one internal or attached ADU and one JADU, are permitted per parcel with a proposed or existing single-family dwelling.

2.

One detached, new construction or conversion of an existing structure, including a detached garage, ADU is permitted for a parcel with a proposed or existing single-family dwelling. The detached ADU may be combined only with a JADU as provided in subsection (A)(1) above.

B.

Multi-family Parcel.

1.

At least one internal ADU is permitted within an existing multi-family dwelling structure up to a maximum of 25 percent of the existing number of multi-family units within the portions of an existing multi-family dwelling structure that are not used as livable space.

2.

On a parcel with an existing multi-family dwelling, the number of ADUs may not exceed the number of existing dwelling units; provided, however, that the number of detached ADUs may not exceed eight.

3.

Not more than two detached ADUs may be located on a parcel where there is a proposed multi-family dwelling.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

The following development standards apply to ADUs:

A.

Maximum Size.

1.

The maximum size of an internal or attached ADU with one bedroom or less may not exceed 850 square feet.

2.

The maximum size of an internal or attached ADU with more than one bedroom may not exceed 1,000 square feet.

3.

Notwithstanding subsections A(1) and (2) above, if an attached ADU would exceed 50% of the floor area of the primary dwelling, the maximum size permitted is 800 square feet.

4.

The maximum size of a detached ADU is as follows:

(a)

850 square feet if one bedroom or less;

(b)

1,000 square feet for a detached ADU that provides more than one bedroom; or

(c)

800 square feet if combined on a lot with a JADU.

B.

Minimum Size. The minimum size of an internal, attached, or detached ADU must be no less than the minimum size necessary for the creation of an efficiency unit.

C.

Maximum Height. The maximum height of an ADU measured from the finished grade is as follows:

1.

A height of 16 feet for a detached ADU on a lot with an existing or proposed single-family or multi-family dwelling unit.

2.

A height of 18 feet for a detached ADU on a lot with an existing or proposed single-family or multi-family dwelling unit that is within one-half of one mile walking distance of a major transit stop or a high-quality transit corridor, as those terms are defined in Section 21155 of the Public Resources Code. An additional two feet in height is permitted to accommodate a roof pitch on the ADU that is aligned with the roof pitch of the primary dwelling unit.

3.

A height of 18 feet for a detached ADU on a lot with an existing or proposed multi-family, multi-story dwelling.

4.

A height of 25 feet or the applicable height limitation in the Zoning Code that applies to the primary dwelling, whichever is lower, for an ADU that is attached to a primary dwelling.

5.

No ADU may exceed two-stories.

D.

Setbacks and Lot Coverage.

1.

An ADU must conform to the development standards for the underlying zone, including, but not limited to, standards for front, rear and side setbacks of at least four feet, and lot coverage. Notwithstanding the prior sentence, no applicable front setback, lot coverage, floor area ratio, or private open space standards will prohibit an ADU that does not exceed 800 square feet of floor area, a height of no more than 16 feet, and has four-foot side and rear yard setbacks, provided the ADU complies with all other applicable standards of this chapter.

2.

No additional setback is required for an existing living area or an accessory structure that is converted into an ADU or a portion of an ADU.

E.

Building and other Related Codes. An ADU must comply with all applicable building, health and fire codes, except that an ADU is not required to provide fire sprinklers if sprinklers are not required for the primary dwelling unit and the construction of an ADU will not trigger a requirement for fire sprinklers to be installed in the existing primary dwelling. In addition, the construction of an ADU will not constitute a Group R occupancy change under the city's building code, as described in Section 310 of the California Building Code (Title 24 of the California Code of Regulations), unless specific written findings based on substantial evidence in the record are made that the construction of the ADU could have a specific, adverse impact on public health and safety.

F.

Driveway Access. An ADU must be served by the same driveway access to the street as the existing primary dwelling unit, unless the ADU has access from a public alley contiguous to the lot, or is located on a corner lot for which secondary access is permitted for parking outside the street side setback. No vehicular access via a bridle trail is permitted.

G.

Entrances. An attached or internal ADU must have a separate entrance to the ADU, which may be located on the front, side or at the rear of the primary dwelling unit and may also be served by a common entrance with the primary dwelling unit. No ADU will be required to provide a new passageway from the ADU to the street.

H.

Expansion of Existing Structure. An internal ADU may include an expansion of not more than 150 square feet beyond the same physical dimensions as the existing primary dwelling or accessory structure; provided, however, any expansion beyond the physical dimensions of the existing primary dwelling or accessory structure will be limited to accommodating ingress and egress.

I.

Exterior Stairs. Exterior stairs should be located at the side or the rear of the primary dwelling to limit visibility from any public street.

J.

H District. If the lot on which the ADU is proposed is located within the horse overlay zone (H District), provisions for horses and horsekeeping areas pursuant to Chapter 17.36 (H District) of this code should be maintained to the extent possible and acceptable to the applicant; provided, however, that the application of such standards may not preclude the development of an ADU otherwise in compliance with chapter or unreasonably restrict the ability of an applicant to create an ADU.

K.

Manufactured Homes and Prefabricated Homes.

1.

A manufactured home is allowed as an ADU provided that it meets the following requirements:

(a)

provides a minimum of 320 square feet of floor area;

(b)

is built on a permanent chassis;

(c)

is designed for use as a single-family dwelling with or without a foundation when connected to the required utilities; and

(d)

includes plumbing, heating, air conditioning, and electrical systems within the home.

2.

A prefabricated or modular home is allowed as an ADU.

L.

Other Buildings and Structures. Any other building or structure constructed on the lot concurrent with or subsequent to the construction of an ADU under this chapter must comply with all applicable development standards of this title.

M.

Replacing or Converting Existing Structures.

1.

An internal ADU may be constructed within the existing structure regardless of whether such structure conforms to the current zoning requirement for building separation or setbacks.

2.

If an existing structure is demolished and replaced with an ADU, an ADU may be constructed in the same location and to the same dimensions as the demolished structure. A demolition permit for a detached garage that will be replaced by an ADU will be reviewed concurrent with the ADU application.

3.

If any portion of an existing structure crosses a property line, the structure may not be converted to or replaced with an ADU. For an existing structure within four feet of a property line, the applicant must submit a survey demonstrating that the structure does not cross the property line.

N.

Utility Services.

1.

All ADUs must be connected to public utilities, including water, electric, and sewer (or on-site septic) services and all such connections are subject to state law and the requirements of the serving utility provider.

2.

Except as provided in subsection (3) below, the city may require the installation of a new or separate utility connection between the ADU and the utility. The connection fee or capacity charge must be proportionate to the burden of the proposed ADU based on either its square feet or the number of drainage fixture unit values as defined in the Uniform Plumbing Code.

3.

No separate connection between an ADU and the utility will be required for an internal ADU within a single-family dwelling, unless the ADU is being constructed in connection with a new single-family dwelling.

O.

Additions to Historic Structures. A building addition to a designated historic resource or potential historic resource, as defined in Chapter 17.38 (Landmark Overlay Zones), for an attached ADU must be inset or separated by a connector that is offset at least 18 inches from the parallel side or rear building wall to distinguish it from the historic structure.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

Design of an attached or detached ADU will be administratively reviewed by the community development department under the city's ADU objective design standards which are available at: https://www.rollinghillsestates.gov/departments/adu.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

A.

Number. The parking requirement for an attached or detached ADU is one open or enclosed parking space per unit. No additional parking, or reconfiguration of existing parking on the lot, is required for an internal ADU.

B.

Location. Required parking spaces may be provided as tandem parking on a driveway. Off-street parking is permitted in setback areas in locations determined by the city or through tandem parking, unless specific findings are made that parking in setback areas or tandem parking is not feasible based upon specific site or regional topographical or fire and life safety conditions.

C.

Exemptions. No parking is required for an ADU in any of the following instances:

1.

The ADU is located within one-half mile walking distance of public transit.

2.

The ADU is located within an architecturally and historically significant historic district.

3.

The ADU is an internal ADU.

4.

When there is a car share vehicle located within one block of the ADU.

5.

When on-street parking permits are required but not offered to the occupant of the ADU.

6.

When a permit application for an ADU is submitted with a permit application to create a new single-family dwelling or a new multi-family dwelling on the same lot, provided that the ADU or the parcel satisfies any other criteria listed in this section.

D.

Conversion of Existing Parking Structures. When a garage, carport, or covered parking structure is demolished in conjunction with the construction of an ADU or converted to an ADU, replacement parking stalls are not required for the demolished or converted parking structure.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

An application for an ADU that meets the requirements of any of paragraphs (1) to (4), inclusive, of subdivision (a) of Government Code section 66323, will not be subject to any of the objective development or design standards in Sections 17.56.060 through 17.56.080 above that are not authorized by or consistent with the provisions of Government Code section 66323.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

An ADU may be rented if the rental term is for a period of 30 consecutive days or longer. The short-term rentals of an ADU for a period of less than 30 consecutive days is prohibited.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

A.

Number. One JADU is permitted per residential lot zoned for single-family dwelling units with an existing or proposed single-family dwelling.

B.

Size. A JADU may have a maximum size of 500 square feet and must be contained entirely within an existing or proposed single-family dwelling. For the purposes of this subsection (B), an existing attached garage is considered part of the single-family dwelling.

C.

Entrance. A JADU must include a separate entrance from the main entrance to the structure, which entrance must be on the side or rear of the primary residence.

D.

Kitchen. A JADU must include an efficiency kitchen that includes the following:

(1)

a cooking facility with appliances (which must include, at minimum, a sink, cooktop, and refrigerator); and (2) a food preparation counter and storage cabinets that are of reasonable size in relation to the size of the JADU.

E.

Owner Occupancy. The primary dwelling unit or the JADU must be occupied by the property owner (subject to certain temporary exceptions such as a medical or business necessity). Beginning one year after the approval date of the JADU, and annually thereafter, the property owner must file an annual report certifying under penalty of perjury that the property owner is the occupant of the primary dwelling unit or the JADU in order to ensure compliance with this condition. This owner-occupancy requirement does not apply if the owner is a governmental agency, land trust, or housing organization.

F.

Short-Term Rental Prohibited. A JADU that is not occupied by the owner of the property in conformance with this section may be rented provided that the rental term is for a period of 30 consecutive days or longer.

G.

Parking. No additional parking is required for a JADU.

H.

Sanitation. A JADU may, but is not required to, include separate sanitation facilities. If separate sanitation facilities are not provided, the JADU must share sanitation facilities with the single-family dwelling unit and must have direct access to the residence from the interior of the JADU.

I.

State Law. A JADU must comply with the requirements of Government Code section 66333-66339.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

A.

The application for an ADU in conformance with the provisions of this chapter will be reviewed by the community development director for compliance with this chapter. The application process will include a site inspection by a member of the community development department to examine the location of the proposed ADU.

B.

If the community development director determines that the application and evidence submitted show that the ADU will comply with the requirements of this chapter, the application will be approved; otherwise, the application will be denied.

C.

An application for an ADU will not be denied on the basis of preexisting nonconforming zoning conditions, building code violations, or unpermitted structures on the subject property that do not present a threat to public health and safety and are not affected by the construction of the proposed ADU.

D.

Any party aggrieved by the decision of the community development director may appeal the decision to the city manager within 15 days from the date of the director's decision. The grounds for such appeal and the city manager's review of the appeal are limited to compliance with the ministerial provisions of this chapter and applicable state law.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

Except as provided under state law, ADUs and JADUs are subject to all applicable permit and inspection fees adopted under Section 3.04.060 of this code, and ADUs are subject to all applicable public facility fees adopted under Chapter 17.74 of this code.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)

Except as expressly provided in this chapter, to the extent that any provisions of this code conflict with any provisions of this chapter, the provisions of this chapter will control. To the extent any provisions of this chapter conflict with state law, the mandatory requirements of state law will control, but only to the extent legally required.

(Ord. No. 752, § 3(Exh. A), 8-26-2025)