junior ADU (JADU) builder
Junior ADU (JADU) builder in Sacramento
A junior ADU (JADU) is a unit of up to 500 sq ft created entirely within your existing home's footprint — typically a converted bedroom — with its own exterior entrance and an efficiency kitchen. A JADU may share a bathroom with the main house and, unlike standard ADUs, usually requires the owner to live on the property. It adds no new square footage.
What a Junior ADU (JADU) is
A junior ADU is the cheapest legal unit you can add, because it lives inside walls you already own. There is no new foundation, no new roof, and often no new utility service — you are carving a self-contained 500-sq-ft suite out of existing space, usually a bedroom with exterior access. It pairs naturally with the larger floor plans in Sacramento's newer subdivisions in Natomas, Elk Grove, and Rancho Cordova, where a downstairs bedroom or bonus room near an exterior wall converts with minimal disruption. The catch is in the definition: it must stay within the existing footprint, it can share a bath, and most jurisdictions require you to occupy the property. Get those three fences right and a JADU is the fastest, lowest-cost way into ADU income.
Best for: Owners who want the cheapest legal unit, or a second unit on the lot.
Not what you need?
These build types are easy to confuse. Here's where to go instead:
- Garage conversion ADU →
Converting the garage instead of an interior room? That's a garage conversion, not a JADU.
- Attached ADU →
Want a full kitchen and bath and new square footage? An attached ADU lifts the 500 sq ft cap.
- Detached ADU →
Want a standalone unit with no owner-occupancy requirement? Build detached.
Who a Junior ADU (JADU) is best for
What's included
- Up to 500 sq ft within the existing home
- Efficiency kitchen + private entrance required
- Can be combined with a detached ADU on the same property
- Lowest total cost of any ADU type
How we build your junior adu (jadu)
This is the build sequence specific to a junior adu (jadu). For what working with Upside feels like start to finish, see how it works.
- Step 01
Footprint & access check
We confirm which interior room can become the JADU and where a code-compliant exterior entrance can go — the defining constraint of this type.
- Step 02
Efficiency-kitchen design
We design the required efficiency kitchen and decide whether the JADU shares the main bath or gets its own within the 500 sq ft.
- Step 03
Wall separation & entrance
We add the dividing wall, the private exterior door, and any needed sound separation so the suite functions independently inside the home.
- Step 04
Systems within the shell
Electrical, the efficiency kitchen's plumbing, and ventilation go in without a new foundation or new exterior square footage.
- Step 05
Inspection & owner-occupancy filing
We pass inspection and help with the deed restriction many jurisdictions require for the owner-occupancy condition.
Size & layout options
- Capped at 500 sq ft, always within the existing home's footprint
- Efficiency kitchen required; a full second bathroom is optional within the size cap
- Most JADUs are a converted bedroom or bonus room with a new exterior door
- No new foundation, roof, or added exterior square footage — that's what separates it from attached
Want pre-designed floor plans with fixed pricing? Browse our ADU models.
What a junior adu (jadu) costs in Sacramento
A junior adu (jadu) in the Sacramento region typically runs $44,000–$160,000 turnkey in 2026, or roughly $200–$320 per square foot with design, permits, and construction included. JADUs are the lowest total cost of any ADU type because you reuse the existing structure and often the existing utilities — no slab, no roof, no service trench. Cost depends mostly on three things: the efficiency kitchen, cutting in the required exterior entrance, and whether you carve out a private bath or share the main home's. A JADU under 750 sq ft is also impact-fee exempt, though at 500 sq ft maximum every JADU clears that line.
| Configuration | Typical size | All-in 2026 cost |
|---|---|---|
| Shared-bath JADU | ~300 sq ft | $85,000 – $130,000 |
| Private-bath JADU | ~400 sq ft | $120,000 – $175,000 |
| Full 500 sq ft JADU | 500 sq ft | $150,000 – $200,000 |
See our full published ADU pricing and what's included, or estimate your specific cost. For a market-wide breakdown, read how much an ADU costs in Sacramento.
Estimate your ADU
Ballpark 2026 turnkey cost, financing, and rental return for your area.
Estimated turnkey cost
$200–$320 / sq ft · incl. design, permits & construction
Estimates only — 2026 regional ranges, not a bid. Your real price depends on site conditions, finishes, and your lot. We confirm with a free feasibility check.
Junior ADU (JADU) timeline
JADUs are the quickest build — often 3.5–6 months. With no foundation or exterior framing, design runs 2–4 weeks, permitting 4–8 weeks, and construction frequently just 6–10 weeks.
Permitting notes for this type
A JADU must stay within the existing footprint, cannot exceed 500 sq ft, requires an efficiency kitchen and an exterior entrance, and may share a bath with the main house. Critically, most jurisdictions require owner-occupancy — you must live in either the main house or the JADU. See the rules guide for the full setback and permit detail.
Full local rules: Sacramento ADU rules, setbacks & permits · 2026 California ADU law
What to watch for with a junior adu (jadu)
Owner-occupancy requirement
Unlike standard ADUs, a JADU usually comes with a recorded deed restriction requiring you to live on the property. That makes it ideal for house-hacking but limits a fully hands-off rental.
Shared vs private bath
Sharing the main home's bath is the cheapest route but limits the tenant pool; carving a private bath into 500 sq ft costs more and tightens the floor plan.
Losing interior space
A JADU converts space you currently use. We map the floor plan so the main home still works for your household after the conversion.
Junior ADU (JADU) FAQs
Generally yes. JADUs usually carry a recorded owner-occupancy requirement — you must live in either the main house or the JADU. Standard detached and attached ADUs don't carry this, which is the main reason investors who want a fully hands-off rental skip the JADU.
It can, but it isn't required. A JADU may legally share the main home's bathroom, which keeps cost down. Adding a private bath within the 500 sq ft limit improves rentability but tightens the floor plan and raises the build cost.
A JADU is carved from interior living space within the home's existing footprint (often a bedroom) and may share a bath; a garage conversion turns the separate garage structure into a unit with its own full facilities. They have different size caps, parking rules, and owner-occupancy conditions.
A Junior ADU is a unit up to 500 sq ft created inside your existing home's footprint, with its own entrance and an efficiency kitchen. JADUs can share a bathroom with the main house and, unlike standard ADUs, may carry an owner-occupancy requirement.
Plan & price your build
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Explore other ADU types
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