Junior ADU interior conversion by CRS Builders in San Diego
family_home Master Suites & Attached Garages

The Power of
the Junior ADU.

A Junior Accessory Dwelling Unit (JADU) is a self-contained living unit up to 500 sq ft created entirely within your existing single-family home. CRS Builders designs and builds JADUs across San Diego County — from layout planning and permitting to complete construction. Perfect for multigenerational living, aging in place, or generating rental income from underutilized space.

The "Missing Middle" Housing Solution

JADUs are unique. Unlike detached ADUs or large room additions, JADUs are created by repurposing an existing master bedroom, basement, or attached garage into a self-contained unit — no new foundation, no new roofline, and minimal disruption to your property.

  • check_circle Must be 500 square feet or less — carved from existing interior space.
  • check_circle Must have an exterior entrance separate from the main residence.
  • check_circle Requires only an efficiency kitchen (sink, counter, small appliances — no gas range required).
  • check_circle May share bathroom facilities with the main residence or have its own dedicated bathroom.
  • check_circle Can be built alongside a full ADU on the same single-family lot — giving you up to 3 units total.
Junior ADU interior kitchen layout by CRS Builders

JADU Conversion Styles

Maximize your existing footprint. We specialize in transforming underutilized square footage into premium rental or family suites — with minimal construction disruption to your daily life.

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Master Suite
Conversion

Carve out an existing master bedroom or basement. By adding an exterior door and efficiency kitchen, you instantly create a legal JADU. This is the most popular option for San Diego homeowners wanting multigenerational living or an aging-in-place solution.

Master suite JADU conversion with private bathroom by CRS Builders San Diego
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Attached
Garage JADU

Transforming your attached garage is the most popular JADU style. It already has walls, a roof, and a separate entrance, keeping the build scope minimal. For a full detached garage conversion (over 500 sq ft), see our garage conversions page.

Attached garage JADU conversion in San Diego by CRS Builders
Regulations

San Diego JADU Requirements

California law (AB 68, SB 13) makes it easy for homeowners to build Junior ADUs. Here's what you need to know about San Diego's specific requirements.

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Maximum Size: 500 sq ft

JADUs must be 500 square feet or less and created within the existing footprint of your single-family home. No new exterior construction required.

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Owner Occupancy Required

Unlike standard ADUs, the property owner must live in either the main home or the JADU. This is the key regulatory difference between ADUs and JADUs.

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Efficiency Kitchen Only

JADUs require an efficiency kitchen with a sink, counter space, and small cooking appliances. No gas range or full-size oven is required — keeping build scope and costs lower.

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Separate Exterior Entrance

Every JADU must have its own exterior entrance — separate from the main home's front door. An interior connecting door to the main house is allowed but not required.

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Stack with a Full ADU

California law lets you build both a JADU (inside your home) and a full detached ADU on the same single-family lot. That's up to three housing units on one property.

Timeline

JADU Build Timeline

JADUs follow the same CRS Builders 5-phase process shown on our process page. Because the work usually happens inside the existing home, the construction phase can be simpler than a detached ADU, but permitting, corrections, inspections, and owner decisions still affect the final schedule.

01

Discovery & Consultation — 1–2 Weeks

We review your goals, walk through the existing home, identify candidate spaces for conversion, and confirm early feasibility items before design work begins.

02

Design & Engineering — 4–8 Weeks

CRS develops the JADU layout, required drawings, efficiency kitchen details, entrance plan, structural or MEP notes, and the documents needed for submittal.

03

Permitting & Pre-Construction — 3–9 Months

We handle plan submission, corrections, city review, approval steps, trade scheduling, and pre-construction planning. Review time varies by jurisdiction and project complexity.

04

Construction — 3–6 Months

Interior framing, efficiency kitchen installation, bathroom work if separate, exterior door work, HVAC, electrical, finishes, and required inspections are coordinated during construction.

05

Final Walkthrough & Handover — 1–2 Weeks

CRS completes punch-list items, final inspection coordination, system review, warranty documentation, and handover so the JADU is ready for family or tenants.

FAQ

Junior ADU FAQs

What is the difference between a JADU and a regular ADU? expand_more

A JADU (Junior ADU) is up to 500 sq ft and must be created within the existing walls of your home — no new foundation or exterior construction. A regular ADU can be up to 1,200 sq ft and can be detached, attached, or a garage conversion. JADUs require owner occupancy and only need an efficiency kitchen, while ADUs require a full kitchen. The advantage of a JADU is that you can build one in addition to a regular ADU on the same lot.

Do I need to live on the property to have a JADU? expand_more

Yes. California law requires the property owner to occupy either the main residence or the JADU itself. This is the primary regulatory difference between JADUs and standard ADUs (which no longer require owner occupancy as of 2025). This makes JADUs ideal for multigenerational families — live in one unit and rent the other.

Can I build a JADU and a detached ADU on the same property? expand_more

Absolutely. California law explicitly allows one JADU plus one detached ADU on a single-family lot. This means you could have three housing units on one property: your main home, a JADU inside it, and a detached ADU in the backyard. Contact us to evaluate your property's potential.

What is an "efficiency kitchen" for a JADU? expand_more

An efficiency kitchen includes a sink, a countertop with at least 15 inches of counter space, small cooking appliances (microwave, hot plate, toaster oven), and storage for food. No full-size gas range or oven is required, which simplifies construction and avoids the need for a gas line extension. Many JADU owners use induction cooktops.

How long does it take to build a JADU in San Diego? expand_more

JADUs use existing space, so the construction scope can be lighter than a detached ADU, but the project still follows a real design-build timeline. CRS Builders uses the same 5-phase process shown on our process page: discovery, design and engineering, permitting and pre-construction, construction, and final walkthrough. Permitting and inspections depend on the jurisdiction, existing conditions, and how many corrections are required.

Is a JADU a good option for aging parents? expand_more

Yes — JADUs are one of the best solutions for aging in place. They allow elderly parents to live independently with their own entrance and kitchen, while remaining under the same roof as family. The optional interior connecting door provides easy access for caregiving while maintaining privacy. Many San Diego families use JADUs as an alternative to assisted living facilities.

Service Area

We Build JADUs Across San Diego.

CRS Builders builds jadus in every major San Diego neighborhood. Click below to learn about regulations and zoning in your area.

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22+ Communities
videocam Free Virtual Consultation

Ready to Build Your JADU?
Let's Build Something Great.

We start every JADU project with a quick, no-pressure video call, not a high-pressure in-home sales appointment. Just a real conversation about your home, your goals, and what's possible within your existing footprint.

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How It Works

15-minute video call • No commitment • Expert advice

Pick a time that works for you using the calendar. We'll send you a video call invite and talk through your JADU goals, timeline, and budget from the comfort of your couch.

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4891 Ronson Ct Suite C, San Diego, CA 92111

Serving All of San Diego County

call

Direct Line

(858) 788-3839

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Email Us Your Plans

info@crsbuildersinc.com

Already have approved plans? CRS can review them and explain the next realistic construction start window.

Project Details