If you have been looking for ways to add more living space or value to your property, you have likely come across the term ADU. But what exactly does that mean, and why is everyone in the DMV area suddenly talking about them?
The Basics: What is an ADU?
ADU stands for Accessory Dwelling Unit (ADU) or Accessory Living Unit (ALU). In simple terms, it is a second, smaller home located on the same lot as your existing house. Think of it as a fully independent living space that has its own kitchen, bathroom, and place to sleep. Whether you call it a “granny flat,” a “carriage house,” or an “in-law suite,” they all fall under the ADU umbrella.
The Different Types of ADUs
There isn’t a “one-size-fits-all” model for an ADU. Depending on your property layout and your goals, there are four main types:
Detached ADU: This is a completely separate building in your backyard, like a small cottage or a converted shed. It offers the most privacy for both the main house and the ADU occupant.
Attached ADU: This is built as an addition to the side or back of your existing home. It shares at least one wall with the main house but has its own separate entrance.
Basement or Interior ADU: Often called a “junior ADU,” this involves converting existing space inside your home—like a walk-out basement or an attic—into a self-contained apartment.
Above-Garage ADU: This is a popular choice for homeowners who already have a detached garage. You simply build a living unit on the second floor above the parking area.
Why Consider One?
ADUs are incredibly versatile. They are perfect for housing aging parents, giving adult children a place to start out, or even creating a dedicated, quiet home office. Because they use existing land, they are often a more sustainable and affordable way to expand.
There are a lot of resources on the web about ADUs, but to find out what is possible in your area, start with your zoning office.
