Accessory Dwelling Units (ADU)—small, self-contained homes built as additional units on existing lots—are becoming a go-to template for quick, affordable housing around the country. This week, New York City mayor Eric Adams announced a $4 million grant funding to support an ADU pilot program. One in five new homes in California are ADUs, a figure that has doubled since 2020, according to the California Department of Finance.
It’s clear that ADUs are here to stay. Across the country, government officials have been seeking ways to expand and streamline the construction of ADUs. Community Planning Collaborative (CPC), a firm based in Berkeley, California which specializes in housing policy and ADU resources, has launched a digital database for locally approved ADU designs. The platform’s growing database currently includes 30 plans from ten different designers.
The California ADU Plans Gallery offers a free public resource for homeowners to browse designs and connect directly with designers to build an ADU. Additionally, local governments can sign up to launch the ADU Plans Gallery later this summer.
“Digital tools like the ADU Plans Gallery help local governments assist their residents through the challenging ADU process and expand housing supply in their existing neighborhoods,” principal at CPC, David Driskell, said in a statement.
As part of California’s initiative to simplify the ADU permitting process, starting January 1, 2025, state law will mandate that all local governments establish a pre-approval process for ADU plans and an online method of connecting interested homeowners with designers. CPC’s web tool effectively meets the state’s goals and streamlines the ADU approval process.
The website contains several features: designers can add pre-approved plans to a gallery, jurisdictions can select prefabricated site plans from CPC’s database, and homeowners can filter the gallery to find plans, comparing floor plans, and estimated costs.
In addition to the California ADU Plans Gallery, CPC provides other ADU-related resources: custom ADU guidebooks for homeowners, an ADU calculator to estimate local costs, and a mapping tool to determine ADU rules at certain addresses.
