Cupertino ADU Permit & Building Guide
Building an ADU in Cupertino is one of the most efficient ways to add extra living space, generate rental income, and increase the long-term value of your property. With Apex Homes’ pre-approved ADU designs, many homeowners are able to move from concept to completion in as little as five months, creating flexible housing that works for both family needs and financial goals.
ADU Regulations in Cupertino
Cupertino follows California’s state ADU standards but has its own local guidelines for single-family and multi-family lots.
For single-family properties, homeowners can build one detached or attached ADU and one Junior ADU (JADU). Detached ADUs may be up to 850 square feet for a one-bedroom and up to 1,000 square feet for two bedrooms or more. JADUs are capped at 500 square feet. Setbacks are typically four feet from side and rear property lines, and height limits are 16 feet for detached ADUs under 800 square feet. Larger units may require additional review.
On multi-family properties, owners can build up to two detached ADUs (up to 1,200 square feet each) and convert existing non-livable spaces, such as garages or storage areas, into ADUs. Up to 25 percent of existing units may also be converted into attached ADUs.
These standards allow flexibility while maintaining neighborhood character, making ADUs a practical and accessible option for many Cupertino homeowners.
The Cupertino ADU Permitting Process
Cupertino has streamlined its ADU permitting process to make projects easier for homeowners. The process starts with verifying property eligibility and preparing a full set of documents, including a site plan, floor plans, structural details, and a Title 24 energy report.
Applications are submitted electronically through Cupertino’s online permitting portal. Review typically takes 60–90 days, but choosing a pre-approved ADU plan significantly reduces review time—often to around 30 days. Once plans are approved and fees are paid, permits are issued digitally, allowing construction to begin without unnecessary delays.
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Pre-Approved ADU Plans in Cupertino
Cupertino offers several pre-approved ADU designs, giving homeowners a faster, lower-cost path to approval. With these models, the city has already completed most of the design and code review, so only site-specific conditions need to be checked.
These plans come with architectural drawings, structural layouts, foundation details, and Title 24 compliance documents. By selecting a pre-approved option, homeowners benefit from faster approvals, lower design costs, and the assurance that the unit meets city standards.
Currently, Cupertino’s pre-approved ADU layouts include:
Why Build an ADU in Cupertino?
Cupertino’s strong housing demand makes ADUs an excellent investment. A well-designed ADU can generate significant rental income: two-bedroom units often rent for $3,000–$4,000 per month, which can add up to $100,000 annually. Beyond the rental potential, ADUs also boost property value, often increasing home equity by six figures.
For many families, ADUs provide flexibility for multigenerational living. They offer private space for aging parents, adult children, or long-term guests, all while keeping loved ones close.
Cupertino also supports ADU development with reduced impact fees, pre-approved designs, and an efficient online permitting system. This makes the process faster and more affordable than in many neighboring cities.
For more detailed information or specific guidance, we can book a free consultation with an Apex Home ADU expert. Let us help you transform your property with a thoughtfully planned ADU today!