ADU Building, Zoning, and Design Regulations for Cupertino, CA

Cupertino is a great place to build an ADU and allows you to add significant value to your property, following recent updates to California‚Äôs ADU laws. Before you start building, make sure you understand Cupertino’s special use regulations for accessory dwelling units.

1

Cupertino ADU Zoning Requirements

Zoning Regulations:

  • On single family properties two units (either internal conversion or detached) are allowed if one is a JADU and one is a detached ADU that is less than 800 square feet.
  • Only one detached ADUs over 800 sqft or one attached ADU is allowed on a single family property. A JADU is not allowed in addition to these.
  • On multifamily properties, the number of conversion ADUs allowed is either 25% of existing dwelling units or one ADU – whichever is greater. There may be no more than 2 detached ADUs on multifamily properties.
2

Setback Requirements for ADUs in Cupertino

  • Setback requirements are determined by the underlying zoning for conversion ADUs on single family properties.
  • Attached ADUs and detached ADUS less than 800 sqft on single family properties must have rear and side setbacks of at least 4 feet. Front setbacks are per the underlying zoning of the property. These standards also apply to detached ADUs on multi family properties.
  • Detached ADUs greater than 800 square feet must comply with Accessory Structure Ordinance. On corner lots, streetside setbacks modified to 4 feet, but ADU may not encroach into required corner triangle.
3

Maximum ADU Size Requirements

Maximum Area:

  • 1 bedroom attached ADUs have a maximum square footage of 850 sqft. Attached single family ADUs with 2 or more bedrooms can have a floor area up to 1,000 square feet. Attached ADUs on a single family property must meet the Floor Area Ratio and Lot Coverage requirements.
  • Detached ADUs that are greater than 800 square feet have the following floor area requirements: 1 bedroom units can be up to 850 sqft; ADUs with 2 or more bedrooms cannot exceed 1,000 square feet.
  • Single family detached ADUs less than 800 square feet have a maximum size of 800 square feet.
  • Detached multifamily accessory dwelling units cannot exceed 1,200 square feet.
  • Internal conversion ADUS on both single and multifamily properties do not have size limitations.
4

Maximum ADU Height Requirements

Maximum Height:

  • New detached ADUs are limited to 16 feet in height. Detached ADUs greater than 800 square feet Must comply with Accessory Structure Ordinance where the height of 16 feet is allowed at the farthest point from the rear and side property lines.
  • Maximum height for attached ADUs will be determined by the property’s underlying zoning.
  • Conversion ADUs may not increase the height of the existing structure.
5

Selling or Renting an ADU in Cupertino

  • An ADU may be rented, but not sold, separately from the principal dwelling unit. However, ADUs, including JADUs, may not be used for short-term rental activity. For JADUs, the owner must occupy either the principal dwelling unit or the JADU.
  • An ADU or JADU may not be rented for a term of less than 30 days.
View All Cupertino ADU Regulations

Custom ADU Builder in Cupertino

Backyard Unlimited has helped our neighbors in Cupertino increase their liveable space and property values by adding accessory dwelling units to their properties.

Over the years, we have worked throughout the greater Silicon Valley area, installing ADUs and backyard structures in San Jose, Pacifica, and Fremont.
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“Wonderful displays of outdoor and indoor possibilities. My questions were answered quickly, with options only experienced by time spent with many customers.”

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Interested in adding an Accessory Dwelling Unit to your property? Use our builder to customize your ADU, then we will contact you to set up an initial consultation to discuss your pricing and other options.

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