Accessory Dwelling Units (ADUs) come in many shapes and sizes but are always a self-contained home that is usually smaller than the main house and legally part of the same property. They must have a kitchen, bathroom, and place to sleep, and typically range from studios under 500 to 1,000-square-foot homes with multiple bedrooms.
Junior Accessory Dwelling Units (JADUs) are within the footprint of your home (or attached garage) and less than 500 square feet. They can share a bathroom with the main home and/or have an efficiency kitchen (generally a sink, smaller appliances, and counter) Construction costs for JADUs are typically much lower. In most cases, the property owner must live on site in either the main home or the JADU.
State law now allows homeowners to have both a JADU and a regular ADU on their property.