Chapter 84.36 — ACCESSORY DWELLING UNITS

San Bernardino County Zoning Code · 2026-06 edition · ingested 2026-07-07 · San Bernardino County

§ 84.36.010 Purpose.

The purpose of this Chapter is to implement Chapter 13 (commencing with § 66310) of Division 1 of Title 7 of the Government Code by establishing regulations for the permitting and development of accessory dwelling units and junior accessory dwelling units.

(Ord. 4504, passed - -2026)

§ 84.36.020 Applicability.

The standards of this Chapter shall apply to accessory dwelling units and junior accessory dwelling units where allowed in compliance with Division 2 (Land Use Zoning Districts and Allowed Land Uses) of this Development Code.

(Ord. 4504, passed - -2026)

§ 84.36.030 Definitions.

The definitions of specific terms in this Chapter are intended to supplement the definitions in Government Code § 66313. To the extent an inconsistency exists, the definitions in Government Code § 66313 shall prevail unless it is determined from the context of this Chapter that the definition was intended to be more restrictive. For purposes of this Chapter:

(a) ACCESSORY DWELLING UNIT means an attached or detached residential dwelling unit, not considered to exceed the allowable density of the parcel, that provides complete independent living facilities for one or more persons with permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel that the single-family or multifamily proposed or existing dwelling is situated. An accessory dwelling unit can include an efficiency unit, as defined in § 17958.1 of the Health and Safety Code, and a manufactured home, as defined in § 18007 of the Health and Safety Code.

(b) EXISTING PRIMARY DWELLING means a legally permitted and constructed primary single-family residence.

(c) JUNIOR ACCESSORY DWELLING UNIT means a unit that is no more than 500 square feet of interior livable space in size and contained entirely within a single-family residence. A junior accessory dwelling unit may include separate sanitation facilities or may share sanitation facilities with the proposed or existing structure and shall comply with the requirements set forth in § 66333 of the Government Code.

(d) LIVABLE SPACE means a space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation.

(e) PRIMARY DWELLING means the single-family dwelling that serves as the primary residence for the lot.

(f) PROPOSED PRIMARY DWELLING means a structure that is the subject of an active building permit application that meets the requirements for permitting a single-family residence or has received building permit approval but has not yet received an occupancy permit.

(Ord. 4504, passed - -2026)

§ 84.36.040 Types of Units Allowed.

(a) Accessory Dwelling Units on Single-Family Lots. The following types of accessory dwelling units are authorized on a lot where allowed in compliance with Division 2 (Land Use Zoning Districts and Allowed Land Uses) of this Development Code.

(1) Attached Unit. An accessory dwelling unit that structurally abuts and is attached to an existing or proposed primary dwelling. An attached unit may be constructed on the side, top, or below the existing or proposed primary dwelling.

(2) Detached Unit. An accessory dwelling unit that is physically separated from the existing or proposed primary dwelling. A detached accessory dwelling unit shall be deemed the primary dwelling if its floor area exceeds that of the existing primary dwelling.

(3) Converted Existing Structure or Space. An accessory dwelling unit that is created from an existing space within an existing or proposed primary dwelling (e.g., basement, attic, attached garage, storage area, or similar area) or an existing space of an accessory structure (e.g., detached garage, shed, storage structure, or other similar existing accessory structure) on the same lot as the primary dwelling. This may include an existing primary dwelling that is converted to an accessory dwelling unit when a larger primary dwelling is established, though the converted dwelling shall still be limited in size to 1,200 square feet.

(b) Junior Accessory Dwelling Unit on Single-Family Lots. A junior accessory dwelling unit contained entirely within the walls of an existing or proposed single-family residence.

(c) Multifamily Accessory Dwelling Unit. An accessory dwelling unit that may be allowed on a lot zoned for multifamily residence and is either attached, detached, or located within the portions of an existing multifamily dwelling that are not used as livable space (e.g., storage rooms, boiler rooms, passageways, attics, basements, garages).

(Ord. 4504, passed - -2026)

§ 84.36.050 Process and Review Procedures.

(a) Ministerial Review. A permit for an accessory dwelling unit or junior accessory dwelling unit is considered and approved ministerially, without discretionary review or hearing, notwithstanding the need for a variance or special use permit.

(b) Processing Times. Within 15 business days of submission, the Department will assess whether an application for an accessory dwelling unit or junior accessory dwelling unit is complete and, if incomplete, provide notice of this determination and a detailed list of missing items based on the submittal criteria. Upon resubmittal of required materials, the Department shall have 15 business days to review the resubmittal and determine whether the application is complete. The Department shall approve or deny the application for an accessory dwelling unit or junior accessory dwelling unit within 60 days of the date the Department received a complete application if there is an existing primary dwelling or multifamily dwelling on the lot. If an application to create an accessory dwelling unit or junior accessory dwelling unit is submitted concurrently with a permit to create a new primary dwelling or multifamily dwelling on the lot, the 60-day review period can be delayed until the primary dwelling or multifamily dwelling receives approval or if the delay is requested in writing by the applicant.

(1) Pre-Approved Plans. The Director, in consultation with the Building Official, shall adopt and maintain a preapproved building plan for a detached accessory dwelling unit consistent with the current triennial California Building Standards Code rulemaking cycle. The preapproved plan, along with the contact information of an applicant that obtained approval of an accessory dwelling unit using a preapproved plan, shall be posted on the Department’s website in accordance with § 65852.27 of the Government Code.

(A) An application for a detached accessory dwelling unit that utilizes a preapproved plan adopted by the Director within the current triennial California Building Standards Code rulemaking cycle, or a plan identical to a plan

approved by the Director within the current triennial California Building Standards Code rulemaking cycle, shall be ministerially approved or denied within 30 days of the date the Department receives a complete application.

(B) An applicant shall pay the same permitting fees that the County charges an applicant seeking approval for the same-sized accessory dwelling unit when reviewing and approving the submission of a preapproved accessory dwelling unit plan.

(c) Nonconforming Conditions. The Department shall not require, as a condition of ministerial approval of a permit application for the creation of an accessory dwelling unit or junior accessory dwelling unit, the correction of nonconforming conditions. An application for an accessory dwelling unit or junior accessory dwelling unit submitted to correct nonconforming zoning conditions, building code violations, or unpermitted structures that do not present a threat to public health and safety and are not affected by the construction of the accessory dwelling unit or junior accessory dwelling unit shall not be denied. Nonconforming zoning condition means a physical improvement on a property that does not conform to current zoning standards.

(d) Unpermitted Junior and Accessory Dwelling Units. The Department shall not deny a permit for an unpermitted accessory dwelling unit or junior accessory dwelling unit that was constructed before January 1, 2020, for the reasons set forth in Government Code § 66332(a). Notwithstanding the above, the Department may deny a permit for an accessory dwelling unit or junior accessory dwelling unit if the Building Official makes a finding that correcting the violation is necessary to comply with the standards specified in § 17920.3 of the Health and Safety Code or the accessory dwelling unit or junior accessory dwelling unit is attached or within a building that is deemed substandard pursuant to § 17920.3 of the Health and Safety Code.

(e) Legal Nonconforming Accessory Dwelling Unit. The expansion of a legal nonconforming structure or use associated with an accessory dwelling unit shall be subject to the provisions of Division 2 (Land Use Zoning Districts and Allowed Land Uses) and § 84.17.080 (Alteration of Nonconforming Uses) of this Development Code.

(f) Sewer. Written confirmation from the sewer district having jurisdiction of the availability of sewer service for the accessory dwelling unit or junior accessory dwelling unit, or written approval from Environmental Health Services for use on an existing or new septic system, shall be obtained prior to the issuance of a permit for the creation of an accessory dwelling unit or junior accessory dwelling unit. Holding tanks shall not be permitted for an accessory dwelling unit or junior accessory dwelling unit.

(g) Water. Written confirmation from the water district having jurisdiction of the availability of water service for the accessory dwelling unit or junior accessory dwelling unit, or written approval from Environmental Health Services for use of an existing or new well, shall be obtained prior to the issuance of a permit for the creation of an accessory dwelling unit or junior accessory dwelling unit.

(h) Fire Safety. Written confirmation from the applicable fire district or fire authority having jurisdiction shall be required prior to the issuance of a permit for the creation of an accessory dwelling unit or junior accessory dwelling unit.

(i) Grading. Approval of site drainage, ingress, and egress requirements from the Department shall be required prior to the issuance of a permit for the creation of an accessory dwelling unit or junior accessory dwelling unit.

(j) Garage Demolitions. Review and issuance of a demolition permit for a detached garage that is to be replaced with an accessory dwelling unit shall be reviewed and issued at the same time with the application for the creation of an accessory dwelling unit.

(k) Flood Protection. An accessory dwelling unit or junior accessory dwelling unit located within a floodplain safety overlay shall comply with Chapter 82.14 (Floodplain Safety Overlay), including but not limited to elevating the lowest finished floor to the required elevation.

(Ord. 4504, passed - -2026)

§ 84.36.060 Rental Terms, Occupancy, Common Ownership.

(a) Rental Terms. An accessory dwelling unit and junior accessory dwelling unit may be rented separately from the primary dwelling or multifamily dwelling in all regions of the County, subject to the following criteria:

(1) Long-Term Rentals. In all regions of the County, an accessory dwelling unit may be rented for a term longer than 30 consecutive days. The rental of a junior accessory dwelling unit shall be for a term longer than 30 consecutive days in all regions of the County.

(2) Short-Term Rentals. In the Mountain and Desert Regions of the County, an accessory dwelling unit may be rented for a term less than 30 consecutive days, provided the short-term rental unit complies with Chapter 84.28 (Short-Term Residential Rentals) and is not a unit constructed pursuant to § 84.36.080(b).

(b) Occupancy. Owner occupancy shall not be required for an accessory dwelling unit. A junior accessory dwelling unit shall require owner-occupancy in the existing or proposed single-family residence in which the junior accessory dwelling unit will be permitted. The owner may reside in either the remaining portion of the single-family residence or the newly created junior accessory dwelling unit. Owner-occupancy shall not be required if the junior accessory dwelling unit has separate sanitation facilities, or if the owner is another governmental agency, land trust, or housing organization. The recordation of a deed restriction, which shall run with the land, shall be filed with the County Recorder’s Office for an application associated with a junior accessory dwelling unit and shall include both of the following:

(1) A prohibition on the sale of the junior accessory dwelling unit separate from the sale of the existing or proposed primary dwelling, including a statement that the deed restriction may be enforced against future purchasers.

(2) A restriction on the size and attributes of the junior accessory dwelling unit that conforms with this Chapter.

(c) Separate Conveyance. The separate sale or conveyance of an accessory dwelling unit of any type is prohibited except when authorized in accordance with § 66431 of the Government Code.

(Ord. 4504, passed - -2026)

§ 84.36.070 Development Standards.

(a) Except as otherwise provided in this Chapter, the development standards for an accessory dwelling unit and junior accessory dwelling unit shall comply with the requirements set forth in Table 84-0 (ADU Building Form) and the restrictions provided herein.

(1) Land Use Zoning District Regulations. An accessory dwelling unit or junior accessory dwelling unit shall comply with all development standards of the land use zoning district in which it is located.

(2) Multi-family Structure Modification. A modification of the footprint of an existing multi-family dwelling that has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.

(3) Location. An accessory dwelling unit may be located in front of the primary dwelling when constructed in compliance with applicable setback standards.

comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
Table 84-0
ADU Building Form(1)
Unit Type Multifamily ADU ADU JADU
Table 84-0
ADU Building Form(1)
Unit Type Multifamily ADU ADU JADU
Lot Area Dimensions
Size: Determined by the underlying zoning district
Width:
--- --- --- --- ---
Depth:
Maximum Width/Depth Ratio:
Density Per Lot(2)
Minimum: None None None
Maximum (Attached): Existing: Up to 25% of
multifamily units
2 units(3) None
Proposed: 2 units
Maximum (Detached): Existing: 8 units; not to exceed
existing primary unit
count
2 units(3) Not allowed
Proposed: 2 units
Maximum (Conversion): Up to 25% of
multifamily units(4)
2 units(3) 1 unit
Unit Size(5,6)
Minimum: 200 square feet 200 square feet 150 square feet
Maximum (Attached): 1,200 square feet(7) 1,200 square feet(7) Not allowed
Maximum (Detached): 1,200 square feet 1,200 square feet Not allowed
Maximum (Conversion): None None 500 square feet
Setbacks(8)
Front: Per underlying zone Per underlying zone Setbacks of the
existing structure
Side - Street Side: 4 feet 4 feet
Side - Interior: 4 feet 4 feet apply per underlying
zone
Rear: 4 feet 4 feet
Detached Unit Separation: 5 feet(9) 5 feet(9)
Lot Coverage
Maximum Coverage: Determined by the underlying zoning district
Building Height(10)
Maximum (Attached): 25 feet 25 feet 25 feet
Maximum (Detached):(11) 18 feet 18 feet N/A
Maximum (Conversion): None(8)
Parking and Loading
Requirements: One uncovered for
each unit(12)
One uncovered for
each unit(12)
None
Miscellaneous Requirements
Sanitation Facilities:(13) Sanitation Facilities:(13) An ADU must have their own sanitation facility. A JADU may include
separate sanitation facilities or may share sanitation facilities with the
existing structure. A JADU without a separate bathroom must include a
separate entrance from the main entrance to the proposed JADU, with an
interior entry to the main living area.
An ADU must have their own sanitation facility. A JADU may include
separate sanitation facilities or may share sanitation facilities with the
existing structure. A JADU without a separate bathroom must include a
separate entrance from the main entrance to the proposed JADU, with an
interior entry to the main living area.
An ADU must have their own sanitation facility. A JADU may include
separate sanitation facilities or may share sanitation facilities with the
existing structure. A JADU without a separate bathroom must include a
separate entrance from the main entrance to the proposed JADU, with an
interior entry to the main living area.
--- --- --- --- ---
Unit Access: A separate exterior entrance from the primary dwelling is required.
Kitchen: An ADU shall include a full kitchen that is separate from the primary
dwelling. A JADU shall, at a minimum, be permitted to include an
efficiency kitchen which shall contain a cooking facility with appliances
and a food preparation counter with storage cabinets that are reasonable in
size in relation to the JADU.
Notes:
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
comply with all development standards of the land use zoning district in which it is located.
(2)_Multi-family Structure Modification._A modification of the footprint of an existing multi-family dwelling that
has less than four-foot side and rear setbacks shall not be required for the construction of an accessory dwelling unit.
(3)_Location._An accessory dwelling unit may be located in front of the primary dwelling when constructed in
compliance with applicable setback standards.
(1) The standards set forth in this table shall not preclude the construction of an ADU with a total floor area limitation of not more
than 800 square feet of livable space with four-foot side and rear year setbacks.
(2) The maximum unit number is a total aggregate maximum regardless of type of ADU.
(3) On a lot five acres or greater, up to three units are allowed.
(4) Multiple accessory dwelling units within the portions of existing multifamily dwelling structures that are not used as livable
space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, if each unit complies with
state building standards for dwellings.
(5) Calculated based on livable space. The minimum unit size shall not prohibit the development of an efficiency unit as defined in §
17958.1 of the Health and Safety Code.
(6) A junior accessory dwelling unit must be contained entirely within the existing space of the single-family residence.
(7) If there is an existing primary dwelling, the total floor area of an attached accessory dwelling unit shall not exceed 50 percent of
the existing primary dwelling and at no time exceed 1,200 square feet.
(8) No setback or building height shall be required for an existing living area or accessory structure or a structure constructed in the
same location and to the same dimensions as an existing structure that is converted to an accessory dwelling unit or to a portion of an
accessory dwelling unit.
(9) Notwithstanding the five foot minimum separation requirement, separation between structures shall comply with the latest
California Building Code adopted by the County. Where a property is located within a Fire Safety (FS) Overlay, the standards of
Chapter 82.13 (Fire Safety Overlay) shall apply.
(10) The height requirements shall not allow for the construction of a unit greater than two-stories.
(11) An additional two feet in height may be allowed, provided that the roof of the ADU matches the roof pitch of the proposed or
existing primary dwelling.
(12) The spaces may be provided as tandem parking on a driveway.
(13) Where the property is less than one-half acres with an existing primary residence, an Advanced Treatment System designed to
accommodate each additional dwelling is subject to approval by Environmental Health Services for the additional dwelling.

(Ord. 4504, passed - -2026)

§ 84.36.080 Development Standards Exemptions.

(a) Development Standards Exemptions. An accessory dwelling unit and a junior accessory dwelling unit are exempt from the following standards:

(1) Fire Sprinklers. Fire sprinklers shall not be required for an accessory dwelling unit and junior accessory dwelling unit if they are not required for the primary dwelling.

(2) Utility Connections. Unless an accessory dwelling unit or junior accessory dwelling unit is constructed with a new primary dwelling, new or separate utility connections shall not be required and shall not be subject to a separate utility connection fee or capacity charge if constructed from existing space of the primary dwelling or accessory structure. This shall not apply to lots served by a septic system and an individual domestic well.

(3) Parking. The parking requirements for an accessory dwelling unit, as set forth in Table 84-0 (ADU Building Form), shall not apply in any of the following instances:

  • (A) The unit is considered a junior accessory dwelling unit.

  • (B) The accessory dwelling unit is located within one-half mile walking distance of public transit.

  • (C) The accessory dwelling unit is located within an architecturally and historically significant historic district

that is listed in the National Register of Historic Places, State Register of Historic Places, or is listed on the official county registry of such places.

(D) The accessory dwelling unit is part of the proposed or existing primary dwelling or a converted accessory structure.

  • (E) When on-street parking permits are required but not offered to the occupant of the accessory dwelling unit.

  • (F) When a car share vehicle is located within one block of the accessory dwelling unit.

(G) When a garage, carport, or covered parking structure is demolished in conjunction with the construction of an accessory dwelling unit or converted into an accessory dwelling unit, the off-street covered parking does not need to be replaced.

(H) When a permit application for an accessory dwelling unit is submitted with a permit application to create a new primary dwelling or a new multifamily dwelling on the same lot, provided that the accessory dwelling unit or parcel satisfies any of the criteria listed in this subdivision.

(b) By-Right Permitting Exemptions. Notwithstanding anything to the contrary, an application for a building permit for an accessory dwelling unit or junior accessory dwelling unit authorized by Division 2 (Land Use Zoning Districts and Allowed Land Uses) shall be approved to create any of the following:

(1) One accessory dwelling unit and one junior accessory dwelling unit per lot with a proposed or existing primary dwelling if all of the following apply:

(A) The accessory dwelling unit or junior accessory dwelling unit is within the proposed space of a primary dwelling or existing space of a primary dwelling or accessory structure. This may include an expansion of not more than 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.

  • (B) The space has exterior access from the proposed or existing primary dwelling.

  • (C) The side and rear setbacks are sufficient for fire and safety.

  • (D) The junior accessory dwelling unit complies with the requirements of Article 3 (commencing with § 66333), Chapter 13, Division 1, Title 7 of the Government Code.

(2) One detached, new construction, accessory dwelling unit that does not exceed four-foot rear and interior side setbacks for a lot with a proposed or existing primary dwelling, provided the total floor area is not more than 800 square feet of livable space and a height limitation as provided in § 66321(4)(b)(A), (B), or (C) of the Government Code, as applicable. An accessory dwelling unit permitted pursuant to this subdivision may be combined with a junior accessory dwelling unit.

(3) Multiple accessory dwelling units within the portions of existing multifamily dwelling structures that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, if each unit complies with state building standards for dwellings:

  • (A) At least one accessory dwelling unit shall be allowed.

  • (B) The maximum number of units shall not exceed 25 percent of the existing dwelling units.

(4) Multiple accessory dwelling units on a lot with a proposed or existing multifamily dwelling, but are detached from that multifamily dwelling and are subject to a height limitation in § 66321(4)(b)(A), (B), or (C) of the Government Code, as applicable, and rear yard and side setbacks of no more than four feet:

(A) On a lot with an existing multifamily dwelling, not more than eight detached accessory dwelling units. However, the number of accessory dwelling units shall not exceed the number of existing units on the lot.

(B) On a lot with a proposed multifamily dwelling, not more than two detached accessory dwelling units. (Ord. 4504, passed - -2026)

§ 84.36.090 Severability.

The Director, in consultation with County Counsel, shall have the authority to waive any provision of this Chapter to the extent the Director determines that any section, sentence, clause, phrase, or portion thereof is inconsistent with Chapter 13 (commencing with § 66310) of Division 1 of Title 7 of the Government Code, as may be amended from time to time, as applied to an application for an accessory dwelling unit or junior accessory dwelling unit. If, for any reason, any portion of this Chapter is determined by the Director to be inconsistent with Chapter 13 (commencing with § 66310) of Division 1 of Title 7 of the Government Code, then the applicable State law shall provide the controlling development standard and all other provisions of this Chapter shall remain valid and enforceable. (Ord. 4504, passed - -2026)