Chapter 17.70 — ACCESSORY DWELLING UNITS AND JUNIOR ACCESSORY DWELLING UNITS

The purpose of this chapter is to establish procedures for reviewing the placement of accessory dwelling units and junior accessory dwelling units in residential and mixed-use zoning districts, address the state's accessory dwelling unit (ADU) and junior accessory dwelling unit (JADU) requirements, as set forth in California Government Code§§ 66310 to 66342, provide a pathway for amnesty for unpermitted JADUs and ADUs, and implement the general plan policies which encourage more affordable rental housing, while maintaining the quality of existing residential neighborhoods.

(Ord. 2025-01 § 2 (part), 2025; Ord. 2020-04 § 2, 2020; Ord. 2017-08 § 2 (part), 2017; Ord. 2010-02 § 1 (part), 2010)

The regulations and standards contained in this chapter shall apply to all new accessory dwelling units (ADU) and junior accessory dwelling units (JADU) in the city, including previously unpermitted ADUs and junior accessory dwelling units (JADU) in the city, including previously unpermitted ADUs and JADUs constructed prior to January 1, 2020, that are legalized, and shall be in addition to any other development standards and regulations contained elsewhere within Title 17 Zoning Code that apply to primary dwelling units (e.g., lighting). ADUs are permitted on all lots zoned to allow single-family and multi-family residences that have an existing or proposed singlefamily or multi-family residence. JADUs are permitted on lots with an existing or proposed single-family residence. For the purposes of this title, ADUs and JADUs are not considered accessory structures as otherwise regulated in Chapter 17.30.

(Ord. 2025-01 § 2 (part), 2025; Ord. 2020-04 § 2, 2020; Ord. 2017-08 § 2 (part), 2017; Ord. 2010-02 § 1 (part), 2010)

A. Application Review.

1. All accessory dwelling units (ADU) and junior accessory dwelling units (JADU) require review and approval through the plan check process, pursuant to the requirements of Section 17.12.030 (Plan Check).

a. Applications for ADUs and JADUs shall be ministerially reviewed by the City within sixty (60) days from the date a completed application is received if there is an existing single-family or multifamily dwelling on the lot.

b. If the permit application to create an ADU or JADU is submitted with a permit application to create a new single-family dwelling on the lot, the City may delay acting on the application for the ADU or JADU until the City acts on the permit application to create the new single-family dwelling. The application to create the ADU or JADU shall still be considered ministerially without discretionary review or a hearing.

• B. All applications for ADUs and JADUs shall include, but are not limited to, the following:

1. A completed building permit application;

2. Proof of ownership of the property or permission from the property owner;

3. Site plan showing the location of any and all easements, structures, parking for both the primary and accessory dwelling units, other improvements, and trees over four (4) inches in diameter;

4. Floor plan showing the square footage of the structure, the floor area, the lot, and the percentage of the lot area covered by the foundations of the accessory and primary dwelling units;

5. Elevations showing all sides of the ADU or changes being made to the single-family home in order to add an ADU or JADU;

6. Colors and materials board, or aesthetic details noted in plan sets;

7. Such other information which the Community Development Director determines is necessary to evaluate the proposed project.

8. Address assignment application for the proposed unit.

9. Permit applications required by the Public Works Department to serve the proposed unit, which may include but is not limited to sewer lateral and encroachment permits.

• (Ord. 2025-01 § 2 (part), 2025; Ord. 2020-04 § 2, 2020; Ord. 2017-08 § 2 (part), 2017; Ord. 2010-02 § 1 (part), 2010)

An accessory dwelling unit (ADU) or junior accessory dwelling unit (JADU) shall meet all of the applicable zoning regulations for the specific zoning district in which it is located, except as provided in this chapter. An ADU or JADU that conforms to the requirements of this

chapter, and any other applicable development standards and regulations contained in Title 17 Zoning Code, shall not be considered to exceed the allowable density for the lot upon which such unit is proposed to be established and shall be deemed a residential use which is consistent with the existing general plan and zoning designations for the lot. Correction of nonconforming zoning conditions shall not be required as a condition for ministerial approval of a permit application for the creation of an ADU or JADU. Notwithstanding the following performance standards for ADUs and JADUs, and the requirements of the underlying zoning districts, the city shall ministerially approve an application for a building permit within a residential or mixed-use zone to create any of the class of ADUs and JADUs specified under California Government Code § 66323 and in accordance with the criteria and requirements provided therein.

• A. Unit Types and Facilities.

1. Accessory Dwelling Unit (ADU).

a. An ADU shall consist of complete independent living facilities including permanent facilities for sleeping, living, eating, cooking, and sanitation. The ADU shall include independent heating and cooling controls, its own kitchen and sink and standard built-in or freestanding appliances, its own bathroom with bathtub or shower, and a separate exterior entrance.

• b. The ADU may either be within an existing structure, attached to the primary dwelling, or detached from the primary dwelling.

2. Junior Accessory Dwelling Unit (JADU). A JADU shall consist of a unit that is no more than five hundred (500) square feet in size and contained entirely within a single-family residence. A JADU may include separate sanitation facilities, or may share sanitation facilities with the existing structure.

• B. Maximum Number of ADUs and JADUs. Any of the following shall be permitted in a residential or mixed-use zone:

1. One (1) ADU and one(1) JADU per lot with a proposed or existing single-family dwelling.

2. Within existing multi-family dwelling structures, a number of ADUs based on twenty-five percent (25%) of the number of existing multi-family dwelling units, with a minimum of one (1) ADU allowed, if all of the following apply:

• a. The unit is within the portions of existing multi-family dwelling structures that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages.

• b. The unit complies with state building standards for dwellings.

3. Multiple ADUs, not to exceed either of the numbers established below, that are located on a lot that has a multi-family dwelling, but are detached from that multi-family dwelling and are subject to height limits and rear and side yard setbacks under this chapter.

• a. On a lot with an existing multi-family dwelling, not more than eight (8) detached accessory dwelling units. However, the number of accessory dwelling units allowable pursuant to this clause shall not exceed the number of existing units on the lot; or

• b. On a lot with a proposed multifamily dwelling, not more than two (2) detached accessory dwelling units.

• C. Development Standards and Requirements for Accessory Dwelling Units.

1. Maximum floor area for attached or detached ADUs.

• a. Fifty percent (50%) of the existing living area of the primary dwelling unit, with a limit of eight hundred fifty (850) square feet for an ADU with one or fewer bedrooms or one thousand (1,000) square feet for an ADU with two (2) or more bedrooms.

b. Where fifty percent (50%) of the existing living area does not allow for an eight hundred (800) square foot ADU, an ADU of up to eight hundred (800) square feet may be allowed;

2. Setbacks.

• a. New ADUs shall have a minimum setback of four (4) feet from the side and rear property lines, and setbacks shall be sufficient for fire and safety;

• b. No setback shall be required for an existing legal structure that is converted to an ADU;

• c. Detached ADUs shall not be less than six (6) feet from the primary dwelling unit, except if this would prohibit the construction of an eight hundred (800) square foot ADU with four (4) foot rear and side setbacks;

d. No setback shall be required for an ADU constructed within an existing legal structure, or in the same location and to the dimensions of an existing legal structure. Such ADUs may include an expansion of not more than one hundred fifty (150) square feet beyond the same physical dimensions as the existing accessory structure. An expansion beyond the physical dimensions of the existing accessory structure shall be limited to accommodating ingress and egress.

3. Height.

• a. Detached ADUs shall not exceed sixteen (16) feet in height, unless the ADU is located within an existing structure.

• i. The maximum allowable height shall be eighteen (18) feet if the lot is within a half-mile walking distance of a transit stop or high quality transit corridor, as defined in Section 21155 of the California Public Resources Code;

• ii. The maximum allowable height shall be eighteen (18) feet if the detached ADU is located on a lot with a multistory, multifamily building.

• b. Attached ADUs shall not exceed the maximum allowable height of the zoning district.

4. Exterior Access and Design.

• a. The ADU shall have its own exterior access.

• b. Any exterior stairs to a second story attached ADU shall be located behind the residence. If location behind the residence is not possible due to site constraints, the project shall include at least one of the following features to obscure visibility from the public right-ofway; incorporate screening into the architectural design; addition of trees or landscaping as screening; and/or use of colors on the stairway that match those used on the structure where the stairs are attached to minimize contrasts.

the residence is not possible due to site constraints, the project shall include at least one of the following features to obscure visibility from the public right-ofway; incorporate screening into the architectural design; addition of trees or landscaping as screening; and/or use of colors on the stairway that match those used on the structure where the stairs are attached to minimize contrasts.

• c. Attached ADUs shall use exterior colors, materials, and architectural details that match the appearance of existing corresponding features on the residence.

• d. No passageway shall be required in conjunction with the construction of an ADU. A passageway means a pathway that is unobstructed clear to the sky and extends from a street to one entrance of the ADU.

5. Location. Detached ADUs shall be constructed at the rear or side of an existing single-family residence and not be constructed in front of the primary dwelling unit.

6. Rentals. Any rental of ADUs must be for terms longer than thirty (30) days.

• D. Development Standards and Requirements for Junior Accessory Dwelling Units.

1. The JADU shall be constructed within the walls of the proposed or existing single-family residence and shall not exceed five hundred (500) square feet.

2. The owner shall occupy the primary residence or JADU.

3. The JADU shall include a separate entrance from the main entrance to the proposed or existing single-family residence.

4. The JADU may include separate sanitation facilities or may share sanitation facilities with the existing structure.

5. The JADU shall include an efficiency kitchen, which shall include all of the following:

• a. A cooking facility with appliances.

• b. A food preparation counter and storage cabinets that are of reasonable size in relation to the size of the junior accessory dwelling unit.

6. Modifications to the exterior of the residence in order accommodate a proposed JADU shall use exterior colors, materials, and architectural details that match the appearance of existing corresponding features on the residence.

• E. Parking and Vehicle Access.

1. The ADU shall be provided with one (1) additional off-street parking space per ADU or bedroom, whichever is less. However, no additional parking spaces shall be required for an ADU which is:

• a. Part of the existing or proposed primary residence or an existing accessory structure;

• b. Located within one-half mile of a public transit stop;

• c. Located within an architecturally and historically significant historic district;

• d. Is located within one (1) block of a car share vehicle; or

• e. In a location where on-street parking permits are required, but not provided to the occupant of the ADU.

2. Replacement parking shall not be required where a garage, carport, covered parking structure, or uncovered parking space is demolished in conjunction with the construction of an ADU or converted to an ADU.

a. A demolition permit for a detached garage that is to be replaced with an ADU shall be reviewed with the application for the ADU and issued at the same time. An applicant shall not be required to post any written notice or placards for demolition of a detached garage that is to be replaced with an ADU, where posting of such written notice or placard may otherwise be required.

3. The parking spaces required for the accessory dwelling unit can be in tandem to the required parking of the primary dwelling unit, as tandem parking on a driveway, may be uncovered, and/or can be located within the front setback if it can be demonstrated that no other option exists. Such parking is allowed unless specific findings that 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.

4. The ADU shall utilize the same vehicular access that serves the primary dwelling unit. If the parcel is a through lot, access for both the single-family home and the ADU shall be limited to one (1) point or side of the lot for both dwelling units.

5. No additional parking spaces shall be required for a JADU.

• F. Construction, Utilities, Connections, and Impact Fees.

1. The ADU shall meet all applicable building and construction requirements as adopted by the city that apply to the construction of single-family detached dwellings, including but not limited to sewer and utility services, as appropriate and unless otherwise exempt by state law.

2. An ADU shall be served by public water and sewer and shall have access to an improved street.

3. An ADU is not considered a new residential use for purposes of calculating connection fees or capacity charges for utilities, including water and sewer service, unless the ADU was constructed with a new single-family dwelling.

4. An ADU is not required to provide fire sprinklers if they are not required for the primary residence. The construction of an ADU shall not trigger a requirement for fire sprinklers to be installed in the existing primary dwelling.

5. An ADU within a primary dwelling unit or an existing accessory structure is not required to install a new or separate utility connection directly between the ADU and the utility or impose a related connection fee or capacity charge, unless the ADU was constructed with a new single-family home or upon separate conveyance of the ADU.

6. JADU Regulations Related to the Primary Residence.

a. For the purposes of providing service for water, sewer, or power, including a connection fee, a JADU is not considered a separate or new dwelling unit from the single-family residence. Service or connection fees for water, sewer, or power established by ordinances and regulations that uniformly apply to all single-family residences shall apply to a single-family residence that contains a JADU.

For the purposes of providing service for water, sewer, or power, including a connection fee, a JADU is not considered a separate or new dwelling unit from the single-family residence. Service or connection fees for water, sewer, or power established by ordinances and regulations that uniformly apply to all single-family residences shall apply to a single-family residence that contains a JADU.

b. A JADU is not considered a separate or new dwelling unit for the purposes of fire and life protection ordinances. Fire and life protection ordinances and regulations that uniformly apply to all single-family residences shall apply to a single-family residence that contains a JADU.

c. A permit to create a JADU shall not be denied due to the correction of nonconforming zoning conditions, building code violations, or unpermitted structures that do not present a threat to public health and safety and that are not affected by the construction of the JADU.

7. Impact fees shall not be charged for ADUs less than seven hundred fifty (750) square feet. Any impact fees charged for an ADU of seven hundred fifty (750) square feet or more shall be charged proportionately in relation to the square footage of the primary dwelling unit.

• G. Operations.

1. Separate Sales.

• a. A JADU shall not be sold or conveyed separately from the primary dwelling unit.

• b. An ADU shall not be sold or conveyed separately from the primary dwelling unit, except:

• i. The ADU or the primary dwelling was built or developed by a qualified nonprofit corporation, and the proposal meets the requirements of California Government Code Section 66340 to 66341.

ii. As otherwise mandated by the California Government Code, or as otherwise allowed if a local ordinance is adopted to provide for the separate conveyance of the primary dwelling unit and accessory dwelling unit or units as condominiums beyond what is described in subsection i.

2. Rental Term. An ADU shall only be rented for rental terms longer than thirty (30) days.

3. Occupancy. If a project proposes a JADU, the owner of the property shall live in either the primary residence or JADU. (Ord. 2025-01 § 2 (part), 2025; Ord. 2020-04 § 2, 2020; Ord. 2017-08 § 2 (part), 2017; Ord. 2010-02 § 1 (part), 2010)

The city may, subject to the availability of funds and approval of the City Council, allow any applicable city development impact fees for accessory dwelling units to be paid from the city's available affordable housing fund for any new accessory dwelling unit rented to eligible very low and low income households after recording a Housing Affordability Control Agreement, subject to the review and approval of the City Attorney that shall run with the property for fifty five (55) years. Owners of accessory dwelling units affordable to very low income households shall be eligible for complete reimbursement of city development impact fees upon recordation of the Affordability Control Agreement. Owners of accessory dwelling units affordable to low income households shall be eligible for reimbursement of seventy-five percent (75%) of the city development impact fees based on the available balance of the city's affordable housing fund established by the City Council for this purpose. Maximum annual rents, adjusted for accessory dwelling unit household size, shall be calculated by the City Manager or his/her designee annually based on published Contra Costa County income limits provided by the State Department of Housing and Community Development. Any reimbursement payment shall be repaid, along with five percent (5%) monthly interest charge, as well as the city's housing affordability monitoring expenses if an affordability control agreement is violated during the affordability period. (Ord. 2020-04 § 2, 2020; Ord. 2017-08 § 2, 2017)

A. Definitions. For the purposes of this section, "unpermitted junior/accessory dwelling units" shall mean JADUs and ADUs built without prior approval pursuant to the requirements of Section 17.12.030 (Plan Check).

• B. Eligibility and Owner Rights. The owner of an unpermitted junior/accessory dwelling unit has a right to request:

1. Amnesty from any violation of a performance standard in PMC Section 17.70.040 if the unpermitted junior/accessory dwelling unit was constructed prior to January 1, 2020; and

2. Delay in enforcement of the Building Code, and local amendments thereof, as adopted under PMC Title 15 if the unpermitted junior/accessory dwelling unit was built prior to the effective date of this section. To qualify for amnesty or enforcement delay, owners must

submit an application as prescribed by the Community Development Director or their designee.

• C. Application Process.

1. Amnesty JADU/ADU. The owner of an unpermitted junior/accessory dwelling unit that can provide suitable proof that said unit was constructed prior to January 1, 2020, may submit an Amnesty JADU/ADU Permit application in the form and manner prescribed by the Community Development Director or their designee. Suitable proof includes but is not limited to:

• a. Assessor's records:

• b. Rental contracts and/or receipts;

• c. Income tax records;

• d. Utility bills;

• e. Contractor's bills; and/or

• f. Written affidavits from former owners, tenants, or neighbors, signed and notarized under penalty of perjury.

2. Enforcement Delay. Owners may request a delay in enforcement for Building Code violations for units built prior to the effective date of this section in the form and manner prescribed by the Community Development Director or their designee. The Building Code enforcement delay shall be for a period of no more than five (5) years on the basis that correcting the violation is not necessary to protect the public health and safety. The Community Development Director or their designee shall grant the owner's Building Code enforcement delay request unless the Community Development Director or their designee makes a finding that correcting the violation is necessary to comply with conditions that would otherwise deem a building "substandard" housing as defined by California Health and Safety Code Section 17920.3. Any future violations by owners or tenants will result in revocation of the delay.

3. Sewer Lateral Compliance. Owners applying for ADU Amnesty shall demonstrate compliance with the city's sewer lateral inspection program.

• D. Fees and Administrative Costs. Applicants shall pay administrative fees, established by City Council resolution, to process Amnesty JADU/ADU Permit applications and enforcement delay requests.

• E. City Support and Resources. To support a pathway to amnesty and increase program participation, the City shall provide:

1. Accessible public information regarding:

• a. The conditions that constitute substandard housing under California Health and Safety Code Section 17920.3; and

• b. The right of property owners to obtain a confidential, third-party inspection from a licensed contractor before submitting an Amnesty ADU/JADU Permit application.

2. An online self-assessment checklist for owners of unpermitted junior/accessory dwelling units interested in pursuing an Amnesty JADU/ADU Permit.

3. Free and confidential staff consultations to discuss amnesty options.

• F. Enforcement Actions.

1. Notice and Compliance Requirements. When issuing notices of violation for unpermitted junior/accessory dwelling units built before the effective date of this section, the city shall, until January 1, 2030. include a statement of the owner's rights to:

• a. Request amnesty for performance standard violations in PMC Section 17.70.040 for units established and occupied before January 1, 2020;

• b. Request a delay in enforcement of the Building Code and related local amendments for units built before the effective date of this section;

• c. Hire a licensed contractor to conduct a confidential third-party inspection before submitting an Amnesty JADU/ADU Permit application to the city.

2. Penalties. Penalties related to zoning or building violations shall be waived during the amnesty and enforcement delay periods. The burden of proof lies with the applicant to demonstrate the date of establishment and occupancy or construction of the unit.

• G. Sunset Provisions.

1. Applications for Amnesty JADU/ADU Permits and enforcement delays will not be approved after January 1, 2030.

2. No enforcement delays shall extend beyond January 1, 2035, at which point this section shall be repealed. (Ord. 2025-01 § 2 (part), 2025)