Accessory Dwelling Units (ADUs)

Current Accessory Dwelling Unit Regulations

Find the current ADU regulations in Chapter 24.16, Part 2 of the Santa Cruz Municipal Code.

Basic Requirements for Accessory Dwelling Units

  • Accessory Dwelling Units (ADUs) are allowed on any property zoned for residential or mixed use, in conjunction with an existing or proposed residential use.
  • ADUs can be created by building a new structure (New Construction Detached ADU), building an addition to an existing residential structure (New Construction Attached ADU), or by converting any existing legal structure such as a garage, workshop, or guest house (Conversion ADU).
  • Certain types of ADUs, called Statewide Exemption ADUs, are required to meet only a limited set of development standards. Generally, these ADUs include New Construction Detached ADUs that are one story and less than 800 square feet or Conversion ADUs of any size within an existing converted building.
  • ADUs that do not meet the definition of a Statewide Exemption ADU are considered Non-Exempt ADUs and are required to meet all of the City's ADU development standards.
  • On parcels with an existing or proposed single-family home (including townhomes on a separate legal parcel) or detached units, property owners may construct one Statewide Exemption new construction detached ADU, one Statewide Exemption conversion ADU, one Non-Exempt ADU, and one Junior ADU if all units comply with the relevant state and local regulations.
  • Parcels developed with an existing multi-unit building (a building containing two or more units, including apartments or condominiums) can have the same number of Statewide Exemption new construction detached accessory dwelling units as the number of regular units, up to a maximum of eight such ADUs. For example, a lot with a fourplex can have up to four Statewide Exemption new construction ADUs. A lot with a 10-unit building is limited to no more than eight Statewide Exemption detached new construction ADUs.
  • Parcels with an existing multi-unit building may also have a minimum of one Statewide Exemption conversion ADU, up to a maximum of 25% of the existing units. Statewide Exemption conversion ADUs on these sites can only be created in buildings or spaces in building that are not used as livable space, which is space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation. These spaces include, but are not limited to, storage areas, parking areas, unused corridors etc.
  • On parcels with a proposed multi-unit building, up to two Statewide Exemption detached new construction ADUs are allowed. Statewide Exemption conversion ADUs are not allowed.
  • New in 2025: ADUs can be mapped as condominiums and sold separately (more information below).
  • Single-family home properties with ADUs are not eligible to participate in the City's Short-Term Rental (STR) Program – the ADU is intended to provide housing for a household member, family, or tenant.
  • Multi-family properties with ADUs may be eligible to participate in the City's Short-Term Vacation Rental Program if the property owner lives on site and the STR is not in the ADU or associated primary dwelling. Please contact the Planning Department's STR staff member for further information.
  • Outside the Coastal Zone, no parking is required for an ADU. Inside the Coastal Zone, one off-street parking space is required for an ADU located within a short distance of the Coast, as shown in the City's GIS layer titled ADU Parking Required. This layer is listed under the GIS Planning Layers list. GIS layer
  • Outside of the Coastal Zone, any parking spaces or areas removed to accommodate an ADU need not be replaced.
  • Inside of the Coastal Zone, parking requirements and replacement requirements vary based on location. Consult with a planner to determine the standards that apply to your parcel.
  • ADUs require a Building Permit with the requisite architectural drawings, energy calculations, green building calculations, and inspections.
  • No public hearing or discretionary permit is required, with the exception that a Coastal Permit may be required for some ADUs within the Coastal Zone.
  • No owner occupancy is required on properties with ADUs.

Statewide Exemption ADUs

Statewide exemption ADUs are specific types of ADUs that are exempt from site development and design review if they meet basic standards for floor area, setbacks, and height. Statewide exemption ADUs can be built on a site with a single-unit building, such as a single family home, townhome, or detached units, or on a site with a multi-unit building such as an apartment or condominium building.

A Statewide Exemption ADU that meets one of the below definitions does not need to meet the development standards for Non-Exempt ADUs. If an ADU does not meet one of the below definitions of a Statewide Exemption ADU, it is considered a Non-Exempt ADU and must meet the City's development and design standards for non-exempt ADUs.

  • A lot with a proposed or existing single-unit building, including a single-family home, townhome, or a detached unit on a site with multiple detached units may have the following statewide exemption ADUs:
    1. One single family Statewide Exemption conversion ADU if all of the following apply:
      • The accessory dwelling unit is within the proposed space of a single-unit building or it is within the existing space of a single-unit building or detached accessory building. This type of statewide exemption accessory dwelling unit does not include a building reconstructed within the three-dimensional space of an existing building to be demolished.
      • If the accessory dwelling unit is within the space of an existing detached accessory building, the accessory dwelling unit may include an expansion of not more than one hundred fifty square feet beyond the same physical dimensions as the existing accessory building. An expansion beyond the physical dimensions of the existing building shall be limited to accommodating ingress and egress.
      • The accessory dwelling unit has an exterior entrance separate from that of the primary dwelling unit.
      • The side and rear setbacks are sufficient for fire and safety.
    2. One single family Statewide Exemption detached, new construction accessory dwelling unit that meets the following standards:
      • The accessory dwelling unit shall be located on a lot with a proposed or existing single-unit building, including a single-family dwelling, townhome, or a detached residential condominium or apartment unit on a site with multiple dwellings.
      • The accessory dwelling unit size shall not exceed eight hundred square feet in floor area.
      • Interior side yard and rear yard setbacks shall be at least four feet.
      • The height of the ADU, measured to the roof peak, shall be up to 16 feet, or it can be up to 18 feet if the ADU is on a lot within one-half 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. This height can be increased an additional two feet to twenty feet to accommodate a roof pitch on the accessory dwelling unit that is aligned with the roof pitch of the primary dwelling unit.
  • A lot with a multi-unit building including two or more attached units, including apartments or condominiums, may have the following statewide exemption ADUs:
    1. Statewide Exemption conversion ADUs for multi-unit buildings. Multiple accessory dwelling units may be created from within the portions of existing multi-unit buildings 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. The number of accessory dwelling units permitted is equivalent to up to twenty-five percent of the number of existing, legally permitted units in the multi-unit building, or one, whichever is greater. When the twenty-five percent limit results in a fraction of a unit, the total number of accessory dwelling units that may be added shall be determined by rounding the fraction up to the next whole number.
    2. Statewide Exemption new construction detached ADUs for multifamily buildings. Multiple detached accessory dwelling units may be constructed on a lot with a multi-unit building, including a residential condominium or apartment building with two or more attached units. Accessory dwelling units shall meet the following standards:
      • A lot with an existing multi-unit building may have up to eight detached accessory dwelling units. However, the number of such accessory dwelling units shall not exceed the number of existing units on the lot.
      • A lot with a proposed multi-unit building may have up to two detached accessory dwelling units.
      • Rear and interior side yard setbacks shall be at least four feet. If the existing multi-unit building has a rear or interior side yard setback of less than four feet, the existing multi-unit building will not be required to be modified to meet this setback.
      • The accessory dwelling units shall meet one of the following height limitations as measured to the roof peak:
        • A height of 16 feet; or
        • A height of 18 feet if the accessory dwelling unit is on a lot 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. This height can be increased an additional two feet to 20 feet to accommodate a roof pitch on the accessory dwelling unit that is aligned with the roof pitch of the primary dwelling unit; or
        • A height of 18 feet for a detached accessory dwelling unit on a lot with an existing or proposed multi-unit, multistory building.

Standards for Non-Exempt New Construction Detached ADUs

If you are building a new, stand-alone structure as an ADU the following zoning standards apply:

  • New Construction Detached ADUs may be the largest of either:
    1. 10% of the net lot area of the parcel, up to a maximum of 1200 square feet of habitable area (definition of net lot area); or
    2. Up to 850 square feet for a studio or 1-bedroom unit, or up to 1000 square feet for units with more than one bedroom.
  • New construction detached ADUs must be setback a minimum of 3' from the interior side and rear property lines. Any portion of the new construction detached ADU over 16' in height must be set back a minimum of 4' from the interior side and rear property lines.
  • The new construction detached ADU may be up to 22' in height to the roof peak.
  • Fire-resistive requirements of CA Residential Code (CACR) R302.1 apply where the distance from the exterior wall to property line is less than 5 feet.
  • The distance between an ADU and any other building on the same lot must be a minimum of 6', measured from respective exterior walls.
  • If any portion of the ADU is located in front of the primary structure, then the front and side yard setbacks are the same as those required for other residential structures in the zoning district.
  • If an accessory dwelling unit does not meet one or more of the standard setbacks for the zone district in which it is located, the entrance to the accessory dwelling unit, access stairs, and second-story decks shall face the interior of the lot unless the accessory dwelling unit is adjacent to an alley or a public street.
  • If an accessory dwelling unit does not meet one or more of the standard setbacks for the zone district in which it is located and it is adjacent to an alley or a public street, the accessory dwelling unit shall be oriented toward the alley or street with the front access door and windows facing the alley or street. The entry facing the alley or street shall include a minimum of twelve square feet of flat, unenclosed, covered area, which may be a projection from the building, or inset, or a combination of the two.
  • Windows that do not meet the standard zone district side or rear setback and that face an adjoining residential property shall be designed to obscure views of that property by ADU occupants, including transom windows, translucent glass, or other methods; alternatively, fencing or landscaping shall be required to provide screening.

Standards for Non-Exempt New Construction Attached ADUs

If you are building an ADU as addition to an existing single-unit building such as a single-family home, townhome, or unit on a site with multiple detached units, the following zoning standards apply:

  • New Construction Attached ADUs may be the largest of either:
    1. 50% of the habitable area of the primary home; or
    2. Up to 850 square feet for a studio or 1-bedroom unit, or up to 1000 square feet for units with more than one bedroom.,) Most site standards that apply to the primary home (height, front setbacks, floor area ratio), based on the zoning district, shall apply to the ADU or ADU portions of the shared structure. *
      *Exception: Certain zone districts require additional side yard setbacks for portions of a structure based on building stories or height. This increased setback does not apply to the ADU.
      *Exception: Side and rear setbacks are set by State Law and must be a minimum of 4'. Any future abandonment of the ADU use will require removal of the portion of the structure that exceeds the setback otherwise required for the zone district.
  • Attached ADUs may be located on any story of the structure, as allowed based on the zone district.
  • Attached ADUs must comply with the height standard established for primary structures in the underlying zone district.
  • Fire-resistive standards for exterior walls and roof projections apply to new additions and requirements for separation between dwellings will apply to all attached ADU's and to JADU's that do not share a freely accessible interior connection with the primary household (per California Residential Code R302.1 and R302.3)

Standards for Non-Exempt Conversion ADUs

If you are building an ADU by converting any existing or entitled legal structure or portion of a structure on a site with a single-unit building, the following zoning standards apply:

  • Conversion ADUs can be created from part of the existing primary structure, from an existing garage, or other legal structure.
  • Legal structures are ones that were either built with permits or that predate the requirement for building permits and are legally non-conforming.
  • Structures being converted may be partially or fully reconstructed and continue to qualify as a Conversion ADU for purposes of zoning review. Structures that are fully rebuilt will be subject to Building Standards applicable to newly constructed buildings, including applicable fees.
  • A Conversion ADU may be any size, based on the size of the structure to be converted.
  • Structures being converted may be expanded by up to 150 square feet of building footprint. Expansion areas must conform with setback and height standards that apply to New Construction ADUs.
  • Structures being converted may be expanded by up to 2' of total height, not to exceed the height limits outlined in the new construction detached and attached ADU sections above.
  • Current zoning site standards do not apply to Conversion ADUs where they are reusing existing legal structures; however, expansion areas are subject to current zoning standards for ADUs.
  • Due to the change of use generally involved with these conversions, the modified building will be required to meet the current building code standards for use as a dwelling.

Requirements for Junior ADUs

  • Junior Accessory Dwelling Units (JADUs) are allowed on any property zoned to allow single family dwellings and that are created in conjunction with an existing or proposed single family dwelling, townhome, or a detached unit on a site with multiple units.
  • One JADU is allowed per lot.
  • The JADU must be attached to the primary dwelling and can be created as part of a new dwelling, as an addition to an existing dwelling, or as a conversion of existing space within the primary dwelling.
  • Setbacks and other site development standards for a JADU are the same as those required for the primary dwelling to which the JADU is attached.
  • The JADU can be up to 500 square feet in size.
  • The JADU must have its own entrance from the outside.
  • The JADU must have a food preparation area that includes appliances, counter space, and storage cabinets.
  • The JADU can have its own bathroom or share a bathroom with the main house. If the bathroom is shared, there must be an internal door to connect the JADU with the main house so that the person who lives in the JADU can access the bathroom without having to go outside.
  • The JADU cannot be sold separately from the primary dwelling.
  • The owner needs to live in either JADU or in the primary dwelling to which the JADU is attached.
  • The property owner will need to record a land use agreement to memorialize these requirements.

Separate Sale of ADUs

  • ADUs can be mapped as condominiums, enabling them to be sold separately from the other unit(s) on the property.
  • On a site with one or more single-unit buildings, any ADUs and the primary dwelling can each be mapped as condominiums and sold separately from each other.
  • A JADU cannot be mapped as its own condominium. The JADU must be on the same parcel as the primary dwelling.
  • On a site with one or more multi-unit buildings, the ADUs can each be mapped as condominiums and sold separately from the other units.
  • Creation of four or fewer condominium units will require approval of a Parcel Map from the Public Works Department. Creation of five or more condominium units will require approval of a Tentative Map from the Department of Planning and Community Development, followed by approval of a Final Map from the Public Works Department
  • The following notice is provided as required by Government Code Section 66342(e):

Notice: If you are considering establishing your primary dwelling unit and accessory dwelling unit as a condominium, please ensure that your building permitting agency allows this practice. If you decide to establish your primary dwelling unit and accessory dwelling unit as a condominium, your condominium plan or any future modifications to the condominium plan must be recorded with the County Recorder. Prior to recordation or modification of your subdivision map and condominium plan, any lienholder with a lien on your title must provide a form of written consent either on the condominium plan, or on the lienholder's consent form attached to the condominium plan, with text that clearly states that the lender approves recordation of the condominium plan and that you have satisfied their terms and conditions, if any. In order to secure lender consent, you may be required to follow additional lender requirements, which may include, but are not limited to, one or more of the following:

(a) Paying off your current lender.

You may pay off your mortgage and any liens through a refinance or a new loan. Be aware that refinancing or using a new loan may result in changes to your interest rate or tax basis. Also, be aware that any subsequent modification to your subdivision map or condominium plan must also be consented to by your lender, which consent may be denied.

(b) Securing your lender's approval of a modification to their loan collateral due to the change of your current property legal description into one or more condominium parcels.

(c) Securing your lender's consent to the details of any construction loan or ground lease.

This may include a copy of the improvement contract entered in good faith with a licensed contractor, evidence that the record owner or ground lessee has the funds to complete the work, and a signed statement made by the record owner or ground lessor that the information in the consent above is true and correct.

FAQs

Do I need to live on the property to build an ADU or JADU?

ADUs can be built on any residential property in the City, regardless of whether the property is owner occupied.

JADUs are subject to a requirement for owner occupancy, compliant with the State Government Code (Sec. 66333(b)).

I built my ADU 10 years ago and got all the required permits at the time. I've been playing by the rules and now I want to sell my property so I can move. Does the owner-occupancy provision still apply to my property, and any future owner?

Owner occupancy is no longer required on any property with an ADU. If you still have an owner-occupancy deed restriction, you can contact the Planning Department to have that restriction removed.

Do I need a permit to build an ADU?

Yes. All ADUs require a building permit – no public hearing or planning permit is required, although some projects within the Coastal Zone will require a Coastal Permit. If an ADU is proposed along with a new home or multi-family structure on a parcel, the city may delay action on the ADU application until action on the primary residential use is finalized.

ADUs that are built in the Coastal Appeal Zone may require a Coastal Permit. Speak to a planner to determine whether your proposed ADU can be exempt or excluded from that requirement.

What features does an ADU need to have?

An ADU is a fully independent living unit with full facilities for sleeping, eating, cooking, and sanitation. They can be small or large but must have a full kitchen (minimum of countertop for food preparation, cooking appliance, space for refrigeration, and kitchen sink) and full bath (minimum of a toilet, sink, and either a shower or a bath). An ADU must have exterior access independent from the primary dwelling.

What is the difference between an ADU and a JADU?

An ADU is a fully independent dwelling unit, which may be built either as an attached or detached structure on the same lot as another existing residential structure. A JADU, or Junior ADU, is a smaller, attached unit that can be built or converted on the same lot with a single-family home that is owner-occupied. See the below table for required and optional features:

Element ADU Jr. ADU
Converted in Accessory Structure Yes No
Converted in existing SFD Yes Yes
New Construction Detached Yes No
New Construction Attached Yes Yes
Full Kitchen Required Allowed, or can share with SFD
Efficiency Kitchen -- Required, as minimum
Full Bathroom Required Allowed, or can share with SFD
Allowed with existing multi-unit buildings Yes, up to 8 New Construction and up to 25% as Conversion No
Maximum Size See above New Construction and Conversion ADU sections 500 sf
Owner Occupancy Not required Required

Can I use a manufactured home as an ADU?

Yes. If the home can comply with state and local building code requirements, including local green building standards, and can be sited on the property in compliance with the zoning code. Any unit that has been inspected and certified by the California Department of Housing and Community Development (HCD) is eligible.

Can I have both an ADU and a JADU on my property?

If the property has one or more single-unit buildings, such as a single family home, townhome, or multiple detached units, and is owner-occupied, yes. This option is not available on sites with multi-unit buildings or investor-owned property because JADUs are only permitted in owner-occupied single-family properties based on the provisions of California State Law.

Can I have both an ADU and a Short-Term Vacation Rental (STR) Permit on my property?

Single-family home properties with ADUs and/or JADUs are not eligible to participate in the City's Short-Term Vacation Rental Program – the ADU/JADU is intended to provide long-term housing for a household member, family, or tenant. Multi-family properties with ADUs may be eligible to participate in the City's Short-Term Vacation Rental Program. Please contact the Planning Department's STR staff member for further information. Short-Term Rentals

There is an existing unit on my property that was built without permits. Can it be legalized?

Yes, with the addition of Jr. ADUs as an option for Single-Family properties and ADUs now available on multi-family properties, nearly all existing unpermitted units are eligible for legalization through the City's ADU legalization program. These units will need to be brought into compliance with health and safety codes related to substandard dwellings, and the City is working to facilitate this process for property owners in order to keep rental housing on the market. Information about the Legalization Program is available on our website.

What can I do to reduce the cost of my project?

There are many factors that can influence the cost of ADU construction, some will be unavoidable, and others can be greatly influenced by considering several factors at the beginning of your planning process. Below are several factors that can influence the cost of a project both in hard and soft construction costs as well as fees.

Type of Project

  • Conversion ADUs are the least expensive option both in terms of permit fees and in terms of actual construction costs. Conversion of existing habitable space will be less expensive than the conversion of existing non-habitable space (such as a storage area or garage).
  • Note that while the zoning definition of a Conversion ADU allows for full demolition and reconstruction, this type of project will trigger Building review as new construction, including the assessment of plan review and permit fees for a newly built, rather than remodeled, structure.
  • Building your ADU as an addition to your existing home may be more cost effective than building a new stand-alone structure, but this will depend on the age and construction of your existing home.
  • The size of your attached ADU can trigger the requirement for fire sprinklers – if the ADU exceeds 50% of the size of the habitable area of your existing home, your project may require the installation of fire sprinklers throughout the entire structure. If you are close to this threshold, consult with City Fire before finalizing the design of your project.
  • Building a new, free-standing ADU is the most expensive type of ADU, both in terms of construction and in the permitting fees that will apply, but it may be the only or best option for your project depending on your site and your goals.
  • Utilizing a manufactured home or prefab construction may be more cost effective, but make sure the product and its placement on your site can comply with local zoning and building codes.
  • ADUs that are less than 750 square feet fall below the threshold for paying school impact fees (around $3.15/square foot).

Site planning

  • Are you locating your ADU adjacent to an alley? Is the alley paved and in good condition? If not, you could be responsible for paving the portion of the alley abutting your property.
  • Are you locating the ADU on a slope? The structure will need to be engineered more carefully and the project may be more expensive to construct.
  • Do you plan to provide driving access for the occupant of the ADU (not required)? Adding additional paved area to your project (for a longer driveway) adds costs for materials as well as drainage considerations.

Do I need to notify my neighbors or have my ADU reviewed at a public hearing?

Most ADUs require only a building permit. Building permits do not require public notice and cannot be appealed. That said, providing courtesy notice to the residents of adjacent lots prior to the start of construction is neighborly.Some ADUs in the Coastal Zone require approval of a Coastal Permit, which does not require a public hearing, but the City does send out a public notice of the permit application to surrounding properties.

Can my ADU/JADU have separate utility meters?

ADUs and JADUs that are completely independent from the main residential unit(s) may have separate utility meters (water, electricity, gas). To be completely independent, the ADU and/or JADU needs to a) have its own cooking facilities, b) have its own sanitation facilities, and c) contain no direct interior access to another unit. Check with the utility provider for more information on obtaining separate utility meters.

Does my ADU need a separate water meter/sewer connection?

ADUs created as Conversion ADUs or New Construction Attached ADUs are not required to install separate connections for water and sewer service but could in some cases exceed the capacity of the existing connection and trigger the need to up-size the existing meter. This circumstance could result in the need to open the street to upsize the water main, which would also trigger additional permits and fees. We recommend consulting with the Water Department early in your planning process to try to identify any issues that are likely to affect your project.

ADUs created as detached New Construction will almost always trigger the requirement for new water and sewer connections and the associated fees.

Will fire sprinklers be required in the ADU? Will adding an ADU trigger the requirement to add sprinklers to my existing home?

The state law currently prohibits the city from requiring fire sprinklers in an ADU when sprinklers are not present or required in the primary home. If you are building an attached ADU that is larger than 50% of the existing habitable space of your primary home (excluding any attached garage), the size of the addition could require that fire sprinklers be added to the entire structure – both the existing home and the new attached ADU. If you are close to the threshold, we recommend consulting with the City Fire Department about your project before submitting your building permit application.

Can I build more than one ADU?

Parcels that are developed with a single-unit building, such as a single-family home, townhome, or multiple detached units can add one statewide exemption new construction ADU, one statewide exemption conversion ADU, and one non-exempt ADU. If the property is owner-occupied a Jr. ADU is also allowed.

Parcels developed with multi-unit buildings, including apartment and condominium buildings that contain two or more units, can add up to eight statewide exemption new construction ADUs (but no more than the number of existing units) as well as statewide exemption conversion ADUs (minimum of 1 and up to 25% of the number of existing units). Please note that, from a Building Code perspective, buildings or sites containing more than two dwelling units have different requirements than single- or two-family dwellings. Please consult a knowledgeable code professional when planning your project.

I own a duplex. Can I build an ADU?

Yes! If your duplex units are attached, you can add up to two statewide exemption, detached new construction ADUs and at least one statewide exemption conversion ADU created from within existing non-livable space like a garage, storage area, or attic. Please note that, from a Building Code perspective, if the units are attached this would create a triplex/fourplex and will have different construction standards and building requirements than for a duplex. Please consult a knowledgeable code professional when planning your project.

If your duplex units are detached, these are considered single-unit buildings, and you can add one statewide exemption detached new construction ADU, one statewide exemption conversion ADU converted from within the space of a legal building, one non-exempt ADU, and, if the owner lives on the property, a Junior ADU.

I own and live in a townhome. Can I build a JADU?

If the townhome sits on a separate legal parcel, you are entitled to build a JADU.

Contact Information

General questions and information about ADUs:

Have questions about legalizing your ADU or if your ADU is legal?

Have questions about building codes and what applies to your existing or new ADU or permit?

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