New planning tool arrives as California prepares for more accessory dwelling units

A California planning firm has launched a new digital tool to help municipalities comply with an upcoming state mandate requiring preapproval processes for accessory dwelling units by January 1, 2025.

The ADU Plans Gallery, developed by CPC through ADUAccelerator.org, allows local governments to manage and display preapproved ADU plans while connecting homeowners with designers and prefabricated options.

Under California state law, all municipalities must establish streamlined review processes for ADU applications, which typically require professional architectural review.

ADUs, also known as granny flats or in-law units, are secondary housing structures built on single-family residential lots and have become a key strategy for addressing California's housing shortage.

The new tool aims to reduce both time and costs for homeowners looking to add these units to their properties while helping local governments meet their legal obligations.

The development comes as California continues to grapple with some of the nation's highest housing costs and lowest homeownership rates.

ADU construction has surged across the state as lawmakers have removed regulatory barriers and streamlined approval processes.

For property developers and homeowners, the standardized plans gallery could significantly accelerate project timelines by eliminating much of the upfront design work traditionally required for ADU permits, potentially making these housing options more financially viable for middle-income property owners.