Our FAQ is broken into three sections: 








Click the arrows above to jump to a specific section or scroll away.

frequently asked questions about building ADUs, Backyard Offices, & Studios

ADU FAQs 

General ADU questions

Regional Questions

Specific Questions

What's an ADU?

An Accessory Dwelling Unit (ADU) is a small, independent home built on the same property as a primary residence.

They are sometimes called backyard cottages, casitas, tiny homes, micro-houses, in-law suites, pool houses, granny flats, or guesthouses. ADUs typically include their own entrance, living space, and may have a kitchen and bathroom, making them versatile for family, guests, or rental income.


What types of ADUs are there?

ADUs can be detached, attached, converted, or built above a garage. Detached ADUs are separate structures, while attached ADUs share a wall with the main house. Garage and basement conversions repurpose existing space, and garage-top ADUs use vertical space without reducing the yard.

How big can an ADU be?

Most ADUs range from 200 to 1,200 square feet, depending on local zoning rules.

Your city or county may limit ADU size by lot coverage, setbacks, or maximum square footage. Always check local ordinances before planning.

Do I need a permit to build an ADU?

Yes, nearly all ADUs require permits.

Permitting ensures the ADU meets safety codes, zoning regulations, and utility requirements. Some cities have streamlined ADU permit processes to encourage development.
 
Very small units without plumbing may not require permitting, but it varies from one place to another.

How much does it cost to build a ADU?

ADUs typically cost between $100,000 and $300,000.
The price depends on the builder, size, finishes, site conditions, and local labor costs.

Detached units usually cost more than garage conversions, but both can add long-term value.

Elbow Room has fully livable units.  The 20x12 Lynda with a full-bath and kitchenette is $103K.  Every model in every size offers a half-bathroom floor plan. They are perfect for guest suites, backyard offices, and pool houses.   

Can an ADU increase property value?

Yes, ADUs almost always increase property value.

They add livable square footage and make a property more attractive to buyers who want flexible housing or rental income.

In competitive markets, homes with ADUs often sell faster and at higher prices.

Can you rent out a backyard ADU?

In many cities, yes — but rules vary.Some areas allow long-term rentals but restrict short-term rentals like Airbnb.

Check your local zoning and rental ordinances before planning to rent out your ADU.

Do ADUs have kitchens or bathrooms?

Most ADUs include a kitchen, bathroom, and living space.
Smaller or simpler units may only have a bathroom and open room, but detached full-size ADUs usually function like small houses.

How long does it take to build an ADU?

Building a livable ADU typically takes 6 to 12 months.

The timeline includes design, permitting, site preparation, and construction. 

What are the benefits of building an ADU?

ADUs provide housing flexibility, rental income, and added property value. They’re ideal for multigenerational living, downsizing, or creating a private home office or studio. Many homeowners build ADUs to balance lifestyle needs with financial benefits.

How are ADU utilities connected.

ADUs usually connect to the main home’s water, sewer, and electrical systems.

Some projects install separate meters for billing or efficiency, but this depends on local codes and budget.

Elbow Room will handle all of this for you.

What are the differences between an ADU and a tiny home?

ADUs are permanent, permitted structures on residential property, while tiny homes can be mobile.

A tiny home on wheels doesn’t usually count as an ADU unless it’s placed on a foundation and permitted under local ADU codes.

At Elbow Room, we use almost an descriptor for an ADU interchangeably: ADU, tiny home, micro-house, casita, in-law suite, guest house, backyard office, studio shed, yoga studio, pool house, home gym, and Elbow Room.

Who lives in an ADU?


ADUs are used by family, renters, and guests.

They can house aging parents, adult children, tenants, or serve as a guest suite, office, or creative studio. Their flexibility is one of the biggest advantages.