What is an Accessory Dwelling Units, an ADU
Does adding an ADU to your home make sense for you.
An accessory dwelling unit, usually just called an ADU, is a secondary housing unit on a single-family residential lot. The term “accessory dwelling unit” is an institutional-sounding name, but it’s the most commonly-used term across the country to describe this type of housing. While the full name is a mouthful, the shorthand “ADU” is better.
The fact that it is a secondary housing unit—rather than a given structural form—is what defines an ADU.
Here are some types of ADU units:
- Detached new construction ADUs, also sometimes called backyard cottages, granny flats, laneway houses, depending on the jurisdiction
- Garage conversion ADUs
- ADUs above a garage or workshop attached to it. In some areas, these may be called garage apartments or carriage houses.
- Addition ADUs or “bump-out ADUs”.
- Basement conversion ADUs, also commonly called basement apartments, in-law units.
- Internal ADUs, where part of the primary house besides the basement is converted to an ADU.
What ADUs have in common.
While their structural forms vary, ADUs share some common traits and face common design and development challenges. For one thing, the fact that they are secondary housing units on single family residentially zoned lots places ADUs into a unique category of housing. And ADUs also have some other distinguishing characteristics that help further define, differentiate, and distinguish them from other housing types.
- ADUs are accessory and adjacent to a primary housing unit.
- ADUs are significantly smaller than the average US house.
- ADUs tend to be one of two units owned by one owner on a single-family residential lot.
- ADUs tend to be primarily developed asynchronously from the primary house by homeowner developers.
- A large range of municipal land use and zoning regulations differentiate ADU types and styles, and dramatically affect their allowed uses
These differentiating characteristics make ADUs a distinct type of housing. Till now, there has been a lack of common understanding around the language and best practices of ADU development.
Adding an ADU to your property can provide several benefits, such as providing housing for family members, simplifying your lifestyle, and increased financial flexibility.
Find your Local Contractor in our Home Improvement Guide >>
