Dublin ADU update 2025: New rules align with California housing laws

Dublin has officially adopted new Accessory Dwelling Unit (ADU) rules to comply with California’s statewide housing mandates, bringing the city into alignment with requirements enforced by the California Department of Housing and Community Development (HCD). The update follows years of pressure on local jurisdictions to remove barriers that slow or restrict ADU development.

‍

According to Independent News (2025), on November 4^th, the Dublin City Council approved the ordinance to ensure its municipal code reflects state laws, including provisions governing setbacks, height limits, utility connections, and streamlined permitting timelines.

‍

Examples:

• Homeowners may build ADUs up to 800 square feet with four-foot side and rear setbacks.
• Larger units are allowed depending on lot size and the main residence.
• Detached units may reach 16 feet in height, or 18 feet if located within a half-mile of a major transit stop.

‍

The city’s previous code allowed similar dimensions but gave the city more local discretion. The move comes as HCD continues monitoring cities for compliance with California’s ADU statutes, particularly those that previously enforced conflicting or overly restrictive local rules.

‍

State law requires cities to allow ADUs and Junior ADUs (JADUs) on most residential lots and prohibits local governments from imposing standards that would make construction “impossible or impractical.” Dublin’s updated ordinance clarifies ministerial review procedures, adjusts zoning language to avoid conflicts with state code, and ensures homeowners can pursue ADU projects without facing unlawful delays. These changes reflect ongoing statewide efforts to expand low-cost housing options while reducing regulatory barriers.

‍

Why this matters

‍

California continues to face a severe housing shortage, and ADUs remain one of the fastest-growing sources of new housing supply. According to the California Department of Finance (2025), ADUs account for a significant share of the state’s new permitted units each year. By updating its local ordinance to meet state law, Dublin reduces legal risk, improves predictability for homeowners, and supports regional housing production goals.

Equally important, the changes help ensure that local jurisdictions remain in compliance with statewide housing enforcement. In recent years, HCD has increased its oversight of municipalities that create barriers to ADU development, including issuing warning letters and compliance reviews. Dublin’s proactive adoption of updated rules positions the city more favorably under this heightened regulatory environment.

‍

Future implications

‍

With these local changes in place, Dublin sets a clearer path for homeowners and small-scale developers to build ADUs under state-aligned standards. However, the real impact will come down to how quickly permits are processed, how the market responds, and whether the units built are accessible and affordable. Cities that update their local codes sooner may attract more ADU development, helping close the gap in housing supply that persists in many suburban California communities.

Quick Tip: If you’re planning to build an ADU or JADU in Dublin, check the city’s updated ordinance to understand new height standards, setbacks, and streamlined review timelines. Aligning your plans with the latest code can significantly reduce processing delays and help your project move forward more efficiently.

‍

Xavier Rodriguez is the CEO of ADU Geeks, San Diego’s leading ADU consulting and project management firm. In 2024, the company was ranked No. 1 on the San Diego Business Journal’s Fastest Growing Private Companies list in the Small Business category, achieving 594.3% revenue growth.