ADU Basics

ADUs are an important tool that will enable us to quickly add year-round rental housing.

Making ADUs easier for homeowners to build could yield up to 1,000 new units in just a few years when larger housing developments take 5, 10, or even 15 years to permit and build.

However, for years many towns on Cape Cod prohibited building ADUs. Governor Baker’s Housing Choice legislation made it easier for towns to pass updated bylaws to allow ADUs, and most towns have done so. The towns of Falmouth and Brewster have had promising success with early efforts to promote ADU construction after the new bylaws passed, with new permits approved for 21 and 26 ADUs respectively. That’s a significant number of new units added to town inventory quickly and at no cost to taxpayers.

ADU Basement Apartment

ADUs can take many forms depending on the property: detached, attached addition, or part of the existing house.

ADU Basics

Benefits of ADUs

  • ADUs can be permitted and built quickly in a matter of months – that’s the speed we need to address our urgent housing crisis

  • Bylaws require year-round leases so they won’t be diverted to short-term rentals

  • Built within existing wastewater limitations and with minimal tree clearing

  • Optimize the use of existing single-family homes

  • Blend into the neighborhood context
  • Enable homeowners to generate income from what is usually their single largest asset
  • Can be built without significant public investment
  • Create flexibility in home use as a homeowner’s needs change throughout their life
Keys in door

ADUs Provide Flexible Home Use for Different Life Situations

First Home
Rent from ADU can make ownership affordable

Young Children at Home
An ADU can house a childcare provider

Empty Nest
Rent can support college or travel expense, tenant can keep watch on property

Aging Parents
Can move into the ADU, or it can house a care provider