ADUs & Jr. ADUs: What's the Difference and Which is Right for You?

In California, housing is tight, and smart homeowners are finding ways to create more livable space right on their own property. Whether it's to earn rental income, move in a family member, or just add long-term value to your home, ADUs and Jr. ADUs are game changers.

But what's the difference between them? Which one makes sense for your property?

At Horn's Construction, we specialize in building both. Let's break it down.

What Is an ADU? (Accessory Dwelling Unit)

An ADU, sometimes called a granny flat or in-law unit, is a self-contained space that's located on the same property as a single-family home.

• It has its own kitchen, bathroom, entrance, and living space

• Can be detached (a standalone unit in the backyard) or attached built onto the home)

• Commonly used as a rental unit or for multi-generational living

• Sizes range from studio layouts to multi-bedroom designs

ADUs are becoming increasingly popular in California due to updated state laws that make the permitting process easier and faster than ever before.

What Is a Jr. ADU? (Junior Accessory Dwelling Unit)

A Jr. ADU is a bit different. Think of it as a smaller, more compact version of an ADU that's created within the existing footprint of your home.

• Built inside the main house and often by converting an existing bedroom

• Has its own separate entrance efficiency, and existing bedroom

• Shares bathroom with the main house

• Maximum size: 500 square feet

Jr. ADUs are great for adult kids, aging parents, or even a home office that can legally be rented out.

Which One Is Right for You?

Feature	ADU	Jr. ADU
Location	Attached or detached	Inside existing home
Kitchen	Full kitchen	Efficiency kitchen
Bathroom	Private	Shared with main house
Max Size	Up to 1,200 sq ft (varies by city)	500 sq ft max
Best For	Rental income, full-time living	Extended family, part-time rental, home office

If you have yard space and the budget, an ADU gives you the most flexibility. But if you’re working within your existing home, a Jr. ADU can still offer incredible value, often at a lower cost and faster timeline.

Why Work with Horn's Construction?

Building an ADU or Jr. ADU is not only about walls and floors, but it's about planning, permitting, and precision. Our team handles it all:

• Full--service design and construction

• Knowledge of local codes and zoning laws

• Fast-tracked permitting

• Experienced with residential and rental property improvements

• Clear timelines, real communication, and high-quality craftsmanship

We're a family- and Veteran-owned business that puts people first, just ask our past clients!

Let's Turn Your Property Into Something More

Whether you're just starting to explore your options or already have plans in hand, Horn's Construction is here to help you bring your ADU or Jr. ADU to life.

Call us at (818) 412-5245