Garage-to-JADU Conversion UP TO 500 SQ FT · SHARED-UTILITY OPTION · SIMPLER PERMIT PATH

The fastest, simplest path to a second living space in your existing footprint.

A Junior Accessory Dwelling Unit (JADU) is built entirely within your home's existing footprint — almost always the attached garage — capped at 500 square feet, and it can share a bathroom or utility connections with the main house. That combination usually means a faster, less expensive permit process than a full ADU, which is why it's often the first option we walk homeowners through.

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Why a JADU Might Fit Your Garage

A JADU isn't a smaller ADU — it's a different category with its own rules.

California's JADU law caps the unit at 500 square feet and requires it to be contained entirely within the existing walls of your home, which an attached garage almost always satisfies without any structural expansion. JADUs are allowed to share a bathroom with the main house and can connect to existing water, sewer and electrical service rather than requiring separate utility connections and a separate meter — the single biggest reason a JADU permit typically moves faster and costs less than a full ADU permit. One tradeoff worth knowing upfront: California law requires either the main house or the JADU to be owner-occupied, which doesn't apply to a standard ADU. We walk through that requirement with every client before design starts.

Attached garage being converted into a Junior ADU with a new entrance door

What's Included

Everything needed to turn an attached garage into a code-compliant JADU.

Feasibility & Slab/Framing Evaluation

We assess your garage's existing slab, framing, ceiling height and wall condition against JADU habitability requirements before any design work starts.

Efficiency Kitchen & Bathroom Layout

JADUs require at minimum an efficiency kitchen; we lay out a compact, functional kitchen and either a shared or dedicated bathroom depending on your goals.

Separate Entrance

State JADU law requires an independent exterior entrance separate from the main house's entrance — we design and frame that entry as part of the conversion.

Egress Windows & Ceiling Height Corrections

Most garages need a new or enlarged egress window and sometimes a raised ceiling to meet habitable-space code — we handle both as part of the build.

Permit Package & Owner-Occupancy Documentation

We prepare the JADU permit application, including the owner-occupancy affidavit most cities require, and manage plan check through approval.

Why It Matters

A JADU done wrong is either not permitted at all, or permitted as something you didn't want.

The most common mistake we see is a homeowner building out a garage as a JADU without confirming the owner-occupancy requirement, the 500-square-foot cap, or whether their specific city allows a JADU on their lot type at all — all of which can turn into a costly correction or an unpermitted structure. We confirm every one of those constraints against your specific address before you commit to a floor plan.

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Service Areas

Also converting garages nearby.

Based in San Jose, working throughout Santa Clara, San Mateo and southern Alameda counties.

Atherton Belmont Campbell Cupertino Dublin East Palo Alto Foster City Fremont Gilroy Hayward Hollister Los Altos Los Altos Hills Los Gatos Menlo Park Milpitas Morgan Hill Mountain View Newark Palo Alto Pleasanton Redwood City San Carlos San Jose San Mateo Santa Clara Saratoga Sunnyvale Union City Woodside

FAQ

Questions homeowners ask us

Yes — California JADU law requires that either the primary residence or the JADU itself be owner-occupied. This is one of the clearest differences from a standard ADU, which has no owner-occupancy requirement. We confirm how this applies to your situation before design begins.

It must have at least an efficiency kitchen (a cooking facility, sink and food storage), and it can either share a bathroom with the main house or have its own — sharing utilities is what typically keeps the permit and construction scope smaller than a full ADU.

In most South Bay cities, yes. Because a JADU stays within the existing structure and can share utility connections, it usually avoids the separate utility meter applications and larger structural review that add time to a detached or independent-utility ADU permit. Exact timelines still depend on your specific city's current plan check volume.

Generally yes, subject to your city's local rules — JADUs can be rented, though short-term rental restrictions and other local ordinances vary. We'll flag anything specific to your city as part of the permit review.

It's a common issue on older homes. Depending on your roof structure, we can sometimes raise a section of the ceiling or adjust the framing to meet habitable-space minimums — we'll assess this during the feasibility review before committing to a design.

Free, No-Obligation Quote

Let's talk about your garage.

Tell us what you're converting it into — a JADU, an ADU, an office — and we'll get back to you with next steps, usually within one business day.

(408) 442-9136