An accessory dwelling unit (ADU) is a residential dwelling unit that is accessory or secondary to a primary residential dwelling unit. It may be like a smaller apartment within a home, detached from the primary structure in a separate building, or constructed within an existing accessory structure (like a garage or basement).

ADUs provide new housing options that may offer relief to communities where existing residents are concerned about being priced out of their own neighborhoods.

They also help create housing options that are more economically and environmentally sustainable. The smaller building footprint also means fewer materials are used in construction, and less energy is required to heat or cool the house.

In 2018, the city enacted an ADU Overlay District for the single-family zoned portions of the Garfield neighborhood, set to expire after two years.

Other cites have added ADUs to their codes to help address concerns over low housing stock and affordability.

What's Next for ADUs?

The City Planning Commission will be introducing and considering legislation to allow Accessory Dwelling Units (ADUs) citywide. Lessons learned from the 2018 pilot program are that fewer zoning code restrictions on ADUs are needed and additional support for homeowners would facilitate additional ADUs.

The City will continue to support the development of ADUs after the passage of this legislation, including a website describing the permitting process and customer service at the OneStopPGH Counter at 412 Blvd of the Allies.

What are the benefits?

  • ADUs are a flexible housing form that can lightly increase the housing supply in a neighborhood by providing small, economical dwelling units that can be utilized for community members to age in place or provide homeowners the ability to earn rental income through construction of a secondary unit.
  • ADUs also diversify the housing stock and give households the ability to live in a more affordable units in a variety of neighborhoods. Families or close-knit communities can stay close together while still maintaining their own space.