The New AARP Livability Index: ADUs Provide Possibilities for Now, and the Future

Among the updated features and data included in the newest version of the AARP Livability Index, released April 18, is the addition of a housing policy measure for accessory dwelling units (ADUs). Typically known as in-law suites or guest houses, ADUs are an essential component of livability because they help enable people to remain in their communities.

The Livability Index’s inclusion of policies supporting ADUs is an important example of how AARP’s regular updates to the tool ensure that the ever-changing landscape of our nation’s cities and neighborhoods is appropriately captured. Today more than ever, ADU policies show a commitment to supporting livability through housing opportunity and choice for people of all ages.

Whether attached to a primary residence or a separate building, ADUs are secondary, smaller dwellings with a kitchen, bathroom, and sleeping area, located on the same parcel as a single-family home. These units can either be located in a basement or garage unit, or situated in an open area on the property, like the backyard.

State and local actions that encourage ADU development improve housing options for community members and make communities more livable. ADUs enhance the versatility of homes for people with a wide range of needs by offering opportunities for caregiving, multigenerational living, and income generation through renting. They also add more housing for people at different incomes. 

Support for Aging in Place

The practice of building multiple housing units on a single lot is centuries old, with landowners building as many homes as they wished, often for extended family, on their property. It wasn’t until the 20^th century, following World War II and the rise of single-family home developments, that local zoning laws were enacted to prohibit more than one home per lot, making these additional dwellings illegal.

Today’s renewed interest in guest houses and in-law suits stems in part from the strong desire of most Americans to remain in their homes and communities as they age, and from the growing problem of housing affordability. ADUs offer many benefits for homeowners and communities including providing flexibility and options for residents as needs change throughout a lifetime.

AARP’s 2021 Community Preferences Survey revealed that over 75 percent of adults 50+ would like to remain in their community as they age. Nearly one in three adults would consider building an ADU on their property with the top reason being so that a loved one who needs care would have a place to stay, according to the survey.

ADUs can also be designed to support people with mobility challenges, allowing them to better maneuver through their homes. While most single-family homes were not built with features that make them easier to get from room to room, an ADU can be thoughtfully designed according to Universal Design principles.

Others might rent out ADU space for extra income to offset costs during retirement, or offer it to friends or a family caregiver. Because ADUs can be built in areas with predominantly single-family homes, these units offer a lower-cost alternative for renters seeking housing in the area.

ADU-Friendly Zoning

Although ADUs are gaining ground in many places across the country, challenges remain with local zoning laws responsible for regulating the location, design, size and occupancy of residential areas. Permitting, and other requirements can frustrate homeowners unfamiliar with the development process.

Further, community opposition often hinders local efforts to allow ADUs. And while ADUs are typically less expensive to build than single-family homes, they can be cost prohibitive to those without access to sufficient funds.

Leading the Way 

AARP has been at the forefront of ADU policy development, working with the American Planning Association to develop a model state statute and a local ordinance as a tool for advocates and legislators alike to work towards productive ADU laws. The resource was updated in 2021 to reflect the learnings from the past two decades.

So far nine states have passed ADU laws thus far; California, New Hampshire, Oregon, Rhode Island, Vermont, Maine, Rhode Island, Hawaii, and Florida. The District of Columbia has also passed an ADU law.

And with support from AARP advocacy efforts and other organizations, eight states and localities updated policies to allow ADU development in 2021. AARP resources to help educate policymakers and communities to promote ADUs include The ABCs of ADUs, a primer on what ADUs are and what they can do; ADUs: A Step by Step Guide to Design and Development, which provides guidance on design and development; and a number of videos and webinars on the subject. And, of course, the Livability Index is there to provide instant feedback on how a community is doing in this highly relevant area of livability.

To check your community’s livability score visit the Livability Index.