Structural & systems · Glossary
Junior Accessory Dwelling Unit
Also called: JADU
A Junior Accessory Dwelling Unit (JADU) is a secondary dwelling under 500 square feet located within the walls of an existing single-family home, typically by converting a bedroom and adding a small kitchen. JADUs can share a bathroom with the main residence and have looser parking and impact-fee requirements than full ADUs.
Why this matters for renovation projects
Junior Accessory Dwelling Unit shows up on permits, contracts, or estimates that Renology covers across LA, San Diego, San Francisco, Seattle, Portland, and Denver. Most homeowners encounter the term once a project is already mid-flight, when there is no time to learn its mechanics without slowing the contractor. Knowing what it means before signing the contract is the difference between a clean project and an avoidable surprise. For how Renology calibrates cost ranges against permit valuations and contractor invoices, see the methodology.