Pre-Designed and Pre-Approved Plans
Save time and money by exploring existing ADU plans that can help spark ideas and serve as a helpful starting point for conversations with your own architect, designer, or builder. In some locations, plans may have already been reviewed for building code compliance, which can help streamline the permitting process. Since every property, budget, and homeowner’s goals are a little different, these plans are best used as inspiration and a foundation for shaping the right fit for your project.
PLEASE NOTE: All existing ADU designs — even pre-approved plans — require planning for your property and other permit applications. Not all designs work on all properties, so ask a professional before purchasing or using a design.
ADU Plans Galleries
Some San Mateo locations have an online ADU Plans Gallery, offering a selection of site-built and/or prefabricated ADU designs. Galleries may include designs that have been pre-approved by local, state, or federal agencies, and using one of these plans may make you eligible for faster review.
