Palo Alto ADU Regulations

So many California regulators are providing additional guidance and assistance for homeowners to expand on their properties. Palo Alto is a Bay Area city that has recently doubled its efforts to guide homeowners in the area. The need for affordable housing is behind these efforts, and ADUs are a great start to expanding on an existing lot or primary residence. This article will provide guidance on Palo Alto’s ADU Regulations.

What is an ADU?

ADU is an acronym for an accessory dwelling unit. The City of Palo Alto defines an ADU in two ways. ADU can be a conversion of an area within an existing structure or a hybrid using the current site and adding surface area. Additionally, an existing structure may be rebuilt in place – meaning it can be a renovation within the same building envelope.

Hybrid conversion ADUs, comprising both existing and proposed floor areas, will not comply with the standard ADU regulations in the City of Palo Alto. The city allows up to 150 square feet to be added to an existing building for ingress and egress – the project will not be considered a hybrid conversion if this criterion is met.

Commonly, ADUs are used as a place of residence for additional people in a home outside of the immediate family unit. This can include a grandparent, child moving back in after college, or even a renter.

City of Palo Alto Guideline

The City of Palo Alto issued a Summary Guide to ADUs and Junior ADUs in November of 2020. The document is essentially a summary of the regulations for accessory dwelling units and junior accessory dwelling units based on the Palo Alto Municipal Code (PAMC) Chapter 18.09. This article will dive into some of the specific regulating factors associated with PAMC Chapter 18.09.

  • One ADU and one JADU are permitted on a lot that has either an existing or proposed single-family dwelling unit.
  • Properties with a JADU require the owner to have the primary residence of the JADU or the single-family home.
  • ADUs less than 750 SF have no impact fees. Larger ADUs will require impact fees based on the proportionality of the primary home’s size.
  • A Deed Restriction will need to be recorded with the County prior to permit issuance of a JADU.
    • A deed restriction is a limitation on how a property can be used. This limits what an owner can do on their property as well as what they can build. It typically involves a homeowner’s association (HOA). HOAs implement standards to uphold property value. A thing to note is that deed restrictions typically run with the land (i.e., do not expire) unless an expiration date is outlined in the document.
  • A street address is required for new dwelling units.
  • ADU/JADUs cannot be rented out for periods less than thirty days.
  • ADU/JADUs cannot be sold separately from primary residences.
  • Fire sprinkler systems may be required for ADUs if the primary residence requires them. Compliance with the California Fire Code is required.
  • ADU/JADUs are not considered new residential uses when calculating utility connection fees. No new utility connections are required.
  • ADUs have minimum appliance requirements, as follows:
    • Minimum two (2) burner range
    • Oven or convection microwave
    • A minimum sixteen cubic foot (16 CF) freezer and refrigerator combination unit
  • Kitchens in ADUs have the following requirements:
    • Counter space for food preparation must be equal to a twenty-four-inch (24”) depth and thirty-six-inch (36”) length
    • The sink must facilitate hot and cold water
  • JADUs have one minimum appliance requirement that differs from the ADU requirements, as follows:
    • A minimum ten cubic foot (10 CF) freezer and refrigerator combination unit
  • Attached ADUs are not permitted to have an internal connection to the primary residence; however, JADUs can have an internal link.
  • All trees that are removed to accommodate the construction of an ADU must be replaced per the Tree Technical Manual requirements. Compliance with Urban Forestry about any specific requirements is necessary.
  • ADU/JADUs proposed on properties that are listed on the City’s historical inventory, the California Register, or the National Register of Historic Places must comply with the Secretary of the Interior’s Standards for treatment of historic properties. Additional information on this requirement can be accessed here: Historic Resources & Permit Review Requirements

The City of Palo Alto published a graphic in the summary guide to assist in understanding the information listed above titled: Development Standard for Units Described in Government Code Section 65852.2(e). Please reference the table below:

Table 1: Development Standards for Units Described in Government Code Section 6582.2(e)

  1. A detached or attached ADU can be built in conjunction with a JADU on a lot with a proposed or existing single-family dwelling unit.
  2. Lofts can count towards the unit’s floor area. To further define lofts, they are where the height from the floor level to the finished roof surface or underside of the rafter exceeds five feet (5’).
  3. There can be a maximum of 150 square feet added for ingress and egress.
  4. Units built in a mapped flood zone are not entitled to any height extensions granted to the primary residence.
  5. Existing attached garages that are converted to JADUs may provide replacement parking, as uncovered spaces, in any configuration on the lot. This may include areas within the front or side street yard setbacks for the property.
  6. Lots with both an ADU and JADU may be exempt from up to a combined 800 square feet of the JADU and ADU from Lot Coverage, FAR, and Maximum House Size calculations.

The Next Steps

Building an ADU or JADU will require additional guidance than the City of Palo Alto’s Summary Guide to ADUs and JADUs. The best approach is to hire skilled professionals familiar with the area and permitting process to assist in obtaining the building permit. Design Everest’s experienced team can assist in consulting the building department and drafting construction plans for adding the ADU or JADU to a primary residence. Contact us to get a free quote and consultation today.

ADUs (sometimes known as secondary dwellings) are compact, attached or detached homes located on the same property as the primary residence. Pre-approved
Adding an extra dwelling unit to your house is an excellent way to increase your living space. Auxiliary apartments are inexpensive housing for independent
Accessory dwelling units, or ADUs, are additional living spaces that can be installed on your property. An ADU can be converted from existing facilities
ADUs, or accessory dwelling units, are extra living spaces that can be built on your property. Depending on the available area and the clients' needs,


Email Subscription

Opt In
This field is for validation purposes and should be left unchanged.

Get a Quote (Simplified)

"*" indicates required fields

Opt In
This field is for validation purposes and should be left unchanged.