Hayward City


August 11, 2022

Hayward, California


Hayward's ADU code has been amended to comply with recent state regulations. The most recent specifications for approving an ADU in this community are listed below.


ADUs and JADUs are generally allowed on properties that are zoned for residential or mixed-use development. Persons interested in building and ADU or JADU in Hayward can search the zoning district for a property using City’s online GIS map at the following website: webmap.hayward-ca.gov


Single-Family Properties

On a lot with an existing or proposed single family home, the maximum is one (1) ADU and one (1) Junior ADU provided the structure can meet the zoning and building code standards.

Multifamily Properties

On a lot with an existing multifamily dwelling unit (2 units or more), multiple attached ADUs are allowed up to 25% of the number of existing units. Attached ADUs must be created through the internal conversion of area not used as livable space, such as, storage rooms, boiler rooms, passageways, attics, basements, or garages. In addition, a maximum of two (2) detached ADUs are also allowed on existing multi-family properties.

Important: Single-family residences on properties with existing or planned ADUs are not regarded as multi-family properties.


The following are the size restrictions for ADUs based on the number of bedrooms:

  • Studio or 1-bedroom units may be up to 850 square-feet, and
  • Units with 2-bedrooms or more may be up to 1,000 square-feet.

For ADUs greater than 1,000 square feet, the total floor area of the ADU cannot exceed 50% of the floor area of the primary dwelling(s) or 1,200 square feet, whichever is less. Floor area is defined as interior areas of dwelling units with ceiling heights of 7 feet or more including basements, storage rooms, and attics but does not include garages, patio covers, or porches. There is no limit on the number of bedrooms.


16 feet tall


The underlying zoning district or any law will not impose any minimum lot size requirements for accessory dwelling units on residential lots. In line with AB68.

Minimum Lot Size

No minimum. ADUs greater than 800 square feet are required to provide the minimum open space requirements of the underlying zoning district of the project site.

Maximum Lot Size

The ADU shall not exceed the maximum lot coverage of the underlying zoning district of the project site; however, lot coverage shall not be imposed for attached or detached ADUs less than 800 square-feet.


ADUs and JADUs must generally be at least 4 feet from the side, rear, and front property lines, 20 feet from the front property line, and 6 feet from any other structures. Depending on the precise site circumstances and whether there are any recorded easements on your property, this may change. Please keep in mind that these are merely the minimum zoning criteria and that, depending on your project, further standards from the California building and fire codes may be necessary.

For ADU conversions of already-existing, legally-permitted structures, no setbacks are necessary. The following setbacks, which are stated below, must be maintained by newly constructed detached and attached ADUs:

  • Street-Side and Interior Side Yard: 4-Feet
  • Rear Yard: 4-Feet
  • Front Yard: Conform to underlying Zoning District
  • Setback from Other Structures: 6-Feet


JADUs are always exempt from providing parking. ADUs do not need to provide parking but have the option to do so in a covered, uncovered, or tandem form provided it complies with the City’s code requirements.


The property owner must always live in either the primary dwelling or the brand-new JADU (for JADUs only). Before a building permit is issued for JADUs, a deed restriction must be filed with the County of Alameda Clerk-Recorder's Office.


Building Inspection Fees

  • $150,000 Valuation for Maverick 392: $1,613.65
  • $174,000 Valuation for Maverick 504: $1,783.66
  • $200,000 Valuation for Maverick 748: $1,968.15

Fire Inspection Fee: $221.00

Haz-Mat Inspection Fee: $330.00 per inspection

Planning/Landscape Inspection Fee: $212.00

Planning Review Fee: $564.00 – $688.00 (may vary according to valuation)

Fire Review Fee: $564.00 – $688.00 (may vary according to valuation)

Administrative Fee: $432.98

Impact Fees

JADUs and ADUs less than 750 square-feet (749 or less) are exempt from affordable housing, park dedication, and school impact fees. ADUs that are 750 square feet or greater are subject to impact fees. Please understand that utility connection and capacity charges for water and sewer are not considered impact fees and still apply.


  • The exterior design of the attached accessory dwelling unit shall appear to be a consistent part of the primary dwelling rather than a separate dwelling unit.
  • ADUs shall be required to have fire sprinklers if either of the following conditions exist:
    ◦ The existing units have fire sprinklers
    ◦ There are any active improvements or additions that would require the existing units
  • ADUs require a 1-hour fire-rated wall that extends from the bottom of the footing to the underside of the roof deck to fully separate the existing multi-family dwelling from the repurposed ADU. If the ADU is a conversion under habitable space of the existing multi-family dwelling, the 1-hour fire rating also applies to the floor/ceiling assembly between the units.
  • The City of Hayward has a local green building regulation called the Reach Code. This ordinance prohibits the use of natural gas in newly constructed detached ADUs that are over 400 square feet. This means that water heaters and space conditioning shall utilize heat pumps and cooking appliances shall be all-electric.
  • ADUs shall not be utilized as commercial short-term rentals (i.e. rentals less than 30 days).
  • All ADUs shall have their own independent address.
  • Park impact and school district fees are applicable for ADUs that are equal to or greater than 750 square feet. Affordable housing fees are applicable for ADUs that are equal to or greater than 750 square feet if the project involves two or more new units.



Planning Division

Inquiries on planning and zoning



You can also visit the City Hall business hours to verify whether a property is eligible for an ADU or JADUs.

Building Division

Inquiries on building permit process, including plan check fees, site inspections, timeframes, submittal requirements and address assignments.



Fire Department

Inquiries on fire sprinkler or fire code requirements


Utilities (water and Sewer)

ADUs may require a new or upgraded water meter connection and new sewer connection fees. For more information, visit the City’s website at


Encroachment Permits

Claudia Moran-Garcia

Assistant Civil Engineer






This quick reference manual should be useful to you while you work on your ADU project. Our in-house permit technician will process your permit on your behalf without adding any markups as part of our service if you choose to construct with us.

Please don't hesitate to schedule a meeting with us if you're interested in building with ADU.Works or to give us a call at (650)-227-4810. We are happy to answer any questions you may have and go over the details of how your permission will be processed. Our staff is eager to hear from you.