Rancho Cucamonga ADU Zoning Rules & Permit Guide

ADU Regulations in Rancho Cucamonga, California

Updated September 29, 2026

In San Bernardino County, Rancho Cucamonga follows California's statewide ADU mandates. The city's suburban master-planned communities may have additional design review standards for accessory units.

Below is a summary of the key zoning rules applicable to Accessory Dwelling Units in Rancho Cucamonga as of 2026. Regulations are governed by California's AB 68 (2020), AB 881 (2021), and AB 3182 (2024) which together establish a statewide ADU framework.

Additional Local Requirements for Rancho Cucamonga

• ADU by right in residential zones
• Minimum 150 sq ft
• Height limit: 16 ft for detached

Frequently Asked Questions About ADUs in Rancho Cucamonga

Can I build an ADU in Rancho Cucamonga?

This California city follows the statewide AB 68 framework. Most single-family lots qualify for by-right ADU development.

What is the maximum ADU size allowed in Rancho Cucamonga?

ADUs in Rancho Cucamonga can be up to 1,200 square feet, subject to the property's zoning and lot coverage limits. Always confirm the exact allowed size with the Rancho Cucamonga planning department before designing your project.

What are the setback requirements for an ADU in Rancho Cucamonga?

ADUs in Rancho Cucamonga generally require setbacks of 4 ft rear, 4 ft side. California state law (AB 68) limits local setback requirements to 4 feet for existing structures, but always verify with local zoning.