Accessory Dwelling Unit

An Accessory Dwelling Unit, or ADU, is a secondary living space built on your property, whether it's a converted garage, basement apartment, or standalone backyard cottage. These versatile additions can generate rental income, house aging parents, or provide space for adult children. From zoning requirements to construction details, we'll help you understand what's involved and connect you with pros who specialize in ADU projects.

Related to ADU Service

ADU Service Articles and Advice
Julia Pelly  •  May 5, 2026
Everything You Need to Know About Accessory Dwelling Units
If you want to extend your living space, consider building an accessory dwelling unit or ADU. Learn more about the definition of ADU, its types, cost, and more.
Rachel Hoffman  •  May 3, 2026
How Much Does an Accessory Dwelling Unit (ADU) Cost to Build? [2026 Data]
Accessory dwelling units can be a smart investment, but your ADU cost will depend on the size, type, and materials you choose. Here’s how it breaks down.
Angi  •  May 3, 2026
How Much Does It Cost to Convert a House to a Duplex? [2026 Data]
Discover the cost to convert a house to a duplex. Learn about average prices, cost factors, permits, and ways to save for your duplex conversion project.
Dan Simms  •  May 3, 2026
ADU vs. In-Law Suite: What’s the Difference?
Confused about the difference between an ADU vs. an in-law suite? Learn what they are, how they differ, and which is right for your situation.
Rachel Hoffman  •  May 3, 2026
ADU vs. Tiny House: What’s the Difference?
ADUs and tiny houses are similar solutions for small living spaces, but there are some key differences. Here’s how you can decide on which is right for you.
Dan Simms  •  May 3, 2026
How Much Value Does an ADU Add to Your Property?
Thinking about building an ADU in or around your home? Learn how much value an ADU adds and whether or not it’s worth the investment in the long run.
Dan Simms  •  May 3, 2026
6 Types of ADUs to Consider
An accessory dwelling unit can provide private space for guests or tenants. Learn about the types of ADUs and how they compare to decide which is best.
Kate Fann  •  May 2, 2026
ADU vs. Guest House: What’s the Difference?
Both ADUs and guest houses offer extra livable space while boosting your property value, but there are some key differences. Learn about ADUs and how they’re unique from guest houses.
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Common ADU Service Questions

Technically, most states allow tiny homes, but it depends on the definition of tiny and whether the structure is permanent. Zoning laws regarding home size and construction are significant factors. For instance, a tiny home may be legal as a recreational vehicle in most areas, but you may only install it on a property if it complies with building and zoning codes.

An ADU is a section of your home that you can feasibly use to house guests or even tenants. Pool houses can be ADUs if they include a kitchen, a bathroom, and a bedroom, but smaller pool houses and pool sheds are more for the homeowner to get more enjoyment out of their pool than for guests.

Yes, you’ll need to get building permits from your local municipality to convert your garage to an ADU. You can get the work covered under a remodeling or general construction permit, which can include permission to run or extend utilities to the space to make it legal. If you also plan on renting the space, you’ll need to apply for a rental permit.

As long as you pull the appropriate permits to build your ADU, it will contribute to your property’s total livable square footage. This is even true for basement conversion ADUs despite the living area sitting below grade. Keep in mind that permanent improvements, especially those that add square footage, tend to increase your home value, which can affect your property taxes.

It’s more affordable to add a home addition than it is to build a standalone ADU. A home add-on will cost between $100,000 and $216,000, depending on the size, while a detached ADU can cost up to $285,000 or more. Add-ons are more affordable than detached ADUs in large part because they are easier to connect to utilities and don’t require trenching and excavation to run new lines to a detached building.