A junior accessory dwelling unit, or JADU, is a smaller accessory dwelling unit which has slightly different building code requirements. Although the rules for JADUs will depend on which city you are in but, here in Redwood City, a JADU is a maximum of 500 square feet. It also must be entirely within the existing home.

While many consider JADUs to be just smaller ADUs, that isn’t technically correct and can lead to some misconceptions. JADUs have different building requirements than other accessory dwelling units. Some make them more convenient than an ADU, and others make them less convenient. We’ll go over the definition of a JADU in Redwood City specifically.

Requirements for Junior ADUs

In Redwood City, a JADU is one that is a maximum of 500 square feet and also:

  • Must be contained in the existing walls of your home or garage
  • Must have a separate exterior entrance
  • Must have either a kitchen or an efficiency kitchen
  • May have its own bathroom or may share a bathroom with the main structure

When you choose an efficiency kitchen for your ADU, you save space. But you still must meet the building code requirements and provide a functional kitchen. An efficiency kitchen must include:

  • A sink
  • A counter
  • A storage unit
  • A cooking appliance

Efficiency kitchens must not have gas or 220v circuits, as both are dangerous in these small kitchens. In addition, the requirements for the size of the storage must meet general California building codes.

Other Facts About JADUs

There are some other interesting requirements and rules you should know about before you begin making plans for a JADU on your property.

First, building a JADU now doesn’t stop you from building an ADU in the future. In Redwood City, you may have one, and only one, JADU and ADU on the same property. JADUs do not count towards the density allowed on your lot. They also are exempt from most lot coverage calculations of your underlying zoning district.

While Redwood City allows you to construct only 500 square feet of an accessory dwelling unit on the second floor, this isn’t much of a restriction for JADUs. That means that, apart from the separate entrance, almost all of your JADU can be built on the second floor of your home. This is highly convenient for some home designs that don’t want to sacrifice that space on the main floor.

One last very important thing about JADUs is that once a property has one, it must be owned-occupied. That means that the homeowner must live in either the main home or the JADU. You cannot rent out both spaces, and neither can anyone who purchases it from you.

Learn More About JADUs

Many homeowners build JADUs in order to rent out the space, accommodate family members, or make their home more valuable before a sale. If you’re considering constructing a JADU in Redwood City, we suggest you reach out to your general contractor first to understand more about what makes them different than ADUs.