Milpitas ADU Permit & Building Guide
At Apex Homes, we’ve designed and built pre-approved ADU homes that provide extra living space, stable rental income, and long-term possibilities in as little as five months. Milpitas is a growing city with high housing demand, making it an ideal market for homeowners to add an ADU.
ADU Regulations in Milpitas
Milpitas 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 can be up to 1,200 square feet, while attached ADUs may not exceed 50% of the primary dwelling, with 1-bedroom units up to 850 square feet and 2-bedroom units up to 1,000 square feet. JADUs are capped at 500 square feet. Setbacks are generally 25 feet front, 4 feet side, and 4 feet rear, though units built in the footprint of an existing structure may not require setbacks. Height limits are 16 feet for single-story detached ADUs. Unit separation is 6 feet from rear structures.
On multi-family properties, owners may build up to two detached or attached ADUs, with similar size limits as single-family lots. Detached ADUs may reach up to 20 feet in height if needed to align roof pitches with the primary dwelling. Existing non-livable spaces, such as garages or storage areas, may also be converted into attached ADUs, with up to 25% of existing units converted. Setbacks and unit separation follow the same rules as single-family lots.
These standards provide flexibility while ensuring units are compatible with the surrounding neighborhood, making ADUs an accessible and practical option for many Milpitas homeowners.
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The Milpitas ADU Permitting Process
Getting an ADU permit in Milpitas begins with confirming your property’s eligibility via the city’s ADU Toolkit or address lookup, checking zoning, lot size, setbacks, and allowable ADU types. Homeowners then prepare permit-ready plans, including architectural, structural, Title 24 energy calculations, site and utility layouts, and demolition plans if necessary.
Applications are submitted via the city’s e-Permits portal. Standard review takes approximately 60 days, while pre-approved ADU designs receive expedited review, cutting the timeline nearly in half. Once approved, inspections for foundation, framing, utilities, and final occupancy are scheduled through the portal, and a Certificate of Occupancy is issued after passing all inspections.
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Why Build an ADU in Milpitas?
Milpitas is an attractive market for ADU investment. With strong housing demand and limited rental options, even a modest ADU can generate steady rental income, providing homeowners with additional monthly revenue while increasing property value. Well-designed units can add significant equity to a property, making ADUs a smart long-term investment.
ADUs also offer flexible living arrangements for multigenerational households. Homeowners can provide private space for aging parents, extended family or live-in caregivers, all while maintaining independence and privacy. These units can also serve as home offices, guest suites, or rental units, giving families versatile options that adapt as needs change.
Additionally, Milpitas encourages ADU construction with clear local standards, relaxed setback and parking requirements, and streamlined permitting. Using pre-approved designs can further simplify the process, making it faster, more cost-effective, and less stressful for homeowners.
For more detailed information or specific guidance, we can book a 1 on 1 with an Apex Home ADU expert. Let us help you transform your property with a thoughtfully planned ADU today!