Accessory Dwelling Unit

An Accessory Dwelling Unit (ADU) is an additional legal housing unit that can be constructed within or as an addition to an existing home or, in some cases, a new detached structure. States, cities and towns have different rules about who can build an ADU. In Massachusetts and Rhode Island, new ADU laws have made it possible for thousands of property owners to build a legal ADU.

  • ADUs help communities take advantage of unused space in existing structures, sustainably adding quality and safe housing units to the market.

  • The rapid development of housing units is a proven tool used in efforts to stabilize and lower the cost of rental homes.

  • Homeowners can develop an additional income stream by building and renting out an ADU, if local ADU laws permit non-owner occupants.

  • ADUs empower families to choose the best housing situation for their needs. Seniors can choose to age safely in-place, near loved ones and caretakers, or earn additional money to supplement a fixed retirement budget.

Types of ADUs

Basement ADU

Attic ADU

Addition ADU

Detached Garage ADU

Attached Garage ADU

Backyard ADU

State ADU Laws

An Accessory Dwelling Unit (ADU) is an additional legal housing unit that can be constructed within or as an addition to an existing home or, in some cases, a new detached structure. States, cities and towns have different rules about who can build an ADU. In Massachusetts and Rhode Island, new ADU laws have made it possible for thousands of property owners to build a legal ADU.

  • ADUs help communities take advantage of unused space in existing structures, sustainably adding quality and safe housing units to the market.

  • The rapid development of housing units is a proven tool used in efforts to stabilize and lower the cost of rental homes.

  • Homeowners can develop an additional income stream by building and renting out an ADU, if local ADU laws permit non-owner occupants.

  • ADUs empower families to choose the best housing situation for their needs. Seniors can choose to age safely in-place, near loved ones and caretakers, or earn additional money to supplement a fixed retirement budget.
  • ADUs help communities take advantage of unused space in existing structures, sustainably adding quality and safe housing units to the market.

  • The rapid development of housing units is a proven tool used in efforts to stabilize and lower the cost of rental homes.

  • Homeowners can develop an additional income stream by building and renting out an ADU, if local ADU laws permit non-owner occupants.

  • ADUs empower families to choose the best housing situation for their needs. Seniors can choose to age safely in-place, near loved ones and caretakers, or earn additional money to supplement a fixed retirement budget.

Get notified when state ADU laws are updated.