Junior ADU — convert existing
space into income.
A Junior Accessory Dwelling Unit (Junior ADU) converts existing attached space — a garage, bonus room, or bedroom — into a fully permitted, self-contained dwelling. Lower cost and faster timeline than a full ADU, same rental income potential.
Junior ADU Conversion
A Junior Accessory Dwelling Unit (Junior ADU) is a unit of up to 500 sq ft created within the footprint of an existing single-family home or attached garage. California law (AB 68) streamlined Junior ADU permitting to make this one of the most accessible and cost-effective ways to add rental income to your property.
Unlike a full ADU, a Junior ADU uses your existing structure — which means no new foundation, no new roof, and dramatically lower construction costs. The conversion typically includes insulation, framing modifications, a kitchenette, a bathroom, and a separate entrance.
Arc Design Build has completed dozens of Junior ADU projects across the San Fernando Valley. We know which approaches get approved fastest and how to finish them to a quality that commands top rental rates.
Our process.
Everything you need
to know.
A Junior ADU is limited to 500 sq ft and must be attached to the primary dwelling. An ADU can be detached and larger. Junior ADUs are typically faster and cheaper.
Yes. An attached garage is one of the most common Junior ADU conversions. We handle structural modifications, insulation, plumbing, and the new exterior entrance.
Yes — California requires the owner to occupy either the primary home or the Junior ADU when renting the other unit.
6–10 weeks of construction after permits. Permitting is usually 2–4 months, faster than a full ADU.
We scope finishes during design. Standard: vinyl plank or tile flooring, mini-split HVAC, kitchenette, full bathroom.
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jadu project?
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