Junior ADU (JADU) Conversion in Cupertino
Convert existing space inside your primary home into a code-compliant Junior ADU with a kitchenette.
The Lowest-Cost Way to Add a Legal Second Unit
A Junior ADU (JADU) is a unit of up to 500 sq ft created entirely within the existing walls of your primary home — most often converting a bedroom-plus-adjacent-space into a self-contained suite with an efficiency kitchen and its own entrance, while sharing a bathroom with the main house or adding a small one.
Because a JADU does not add square footage to the building envelope, it is typically the fastest and least expensive ADU type to permit and build — a strong fit for Cupertino's excellent school district, where multi-generational living near Cupertino High or Monta Vista High is a common driver for this project.
- Uses existing space inside your home — no new foundation or roof
- Efficiency kitchen (cooktop, sink, small fridge) required by code
- Can share a bathroom with the main home or have its own
- Owner-occupancy of the primary home may be required — we confirm current rules
Frequently Asked Questions
What is the difference between a JADU and an ADU?
A JADU is up to 500 sq ft, built entirely within your existing home's walls, and requires only an efficiency kitchen. A full ADU can be a separate structure with a complete kitchen and is typically larger.
How much does a JADU conversion cost?
JADU conversions typically run $65,000 to $120,000 depending on existing layout and finish level, since the structural shell is already in place. We give a firm quote after a walk-through.
Do I have to live in the house to have a JADU?
California law has historically required owner-occupancy for JADUs (in the main house or the JADU itself). We can confirm the exact current requirement for your property before you commit.
Can I have both a JADU and an ADU on the same lot?
In many cases yes — state law allows a JADU and an ADU on the same single-family lot together. We evaluate your specific lot to confirm.