The Evolving Promise and Potential of the Granny Flat


It is hard to argue that an extra small house wouldn’t be beneficial to most homeowners, no matter their age. The relative scarcity of “granny flats” is less a result of their usefulness than it is a matter of the popular perceptions and legal contexts surrounding these units. This article reviews how cultural, financial, and regulatory contexts continue to evolve and what these changes might mean for the future of this housing type as a solution for older adults.

Key Words:

granny flat, dower houses, accessory dwelling units, Mom and Pop, multifamily, tiny homes, missing middle

The perception and legality of the granny flat have changed significantly over the past two decades, in large part due to interest in other forms of small-house and multifamily living, a growing affordability crisis, and America’s aging population.

During the latter part of the 20th century, accessory dwelling units (ADU) were marketed to older adults as one of many options that might meet an aging person’s changing needs. These ADUs were envisioned and used as accommodations for a live-in caregiver, as an affordable option for moving an older parent onto the property of his or her adult children, or even for an adult child to occupy temporarily while giving care to a parent in the main house. But with changes in this housing type and in the larger housing market, potential uses of the granny flat have expanded, as has the variety of their design and function.

Granny Flats, Dower Houses, and a Bit of Housing History

Granny flats—places for adult children to accommodate an aging parent—have been tucked into communities for centuries, and from their earliest days were a means of addressing housing, financial, and-or potential care concerns. In medieval England, estates were passed from the lord of the manor to a male descendant. The lord’s wife, the lady of the manor and mother of the heirs, was not part of the succession chain. Children, rather than widows, inherited estates. The widowed lady, or “dowager,” traditionally would move into a smaller residence, known as the dower house, on the estate property, making room for the next generation to take up residence in the principal manor. Dower houses remained an accepted housing type for many centuries and, by the 19th century, were nicknamed “granny flats,” even though they could be quite opulent dwellings.

The practice of living “communally,” with multiple families and households located on a single property—whether on the grand manor estates of the Gilded Age or in the diverse housing stock of increasingly urbanized industrial centers—continued across America into the 20th century. After World War II, however, housing was built on an unprecedented scale, in order to provide returning military veterans with homes in which they could raise families. Never in the history of urban settlement has the landscape been shaped so singularly for the nuclear family (specifically, a mother, father, and two or three children). This building boom excluded most other household compositions and housing types.

Granny flats have been tucked into communities for centuries.

By the 1960s, as veterans aged, the postwar, three-bedroom–two-and-a-half-bath housing stock was supplemented by age-segregated housing developments constructed outside the traditional nuclear family neighborhoods. Specialized housing tailored to specific stages of older adult living began to emerge, and included active adult retirement communities such as Sun City, Arizona, and nursing homes for frailer older adults. These new housing types, which proliferated across the United States, clustered older adults together, often segregating them from the rest of the community through geographic distance, gates, and other barriers. These new forms of “senior living” were in many ways the antithesis of the centuries-old granny flat.

It was not until the last decade of the 20th century that the generational integration that had been a hallmark of the early dower house returned as a goal of urban planning. As the senior housing market began to evolve and the Baby Boom Generation’s impending retirement neared, granny flats were reintroduced as a building type that could help to mix older generations back into the detached, single-family landscape. Often, such flats were touted as a convenience for adult children responsible for caregiving—the granny flat kept the frail parent close by and easier to assist while caregivers performed their daily duties.

By the turn of the 21st century, increasing demands on caregivers led to the creation of the “granny pod,” a granny flat outfitted with remote monitoring capabilities and other caregiving support technologies. Alternatively, it was proposed that the older adult could remain in the main house with a caregiver living in the granny flat, but the focus continued to be on the needs (e.g., convenience, proximity) of the caregiver, not necessarily on the needs of the older adult. While there was much discussion among designers, planners, and senior housing advocates about the many imagined possibilities of a granny flat renaissance, the proposition was largely speculative, as few places in America had zoning laws that allowed granny flats, or as they are referred to in zoning language, accessory dwelling units (ADU).

Over the past two decades, concerns surrounding the granny flat have begun to converge with other, initially unrelated movements in the United States, changing the appeal and the legality of these units, and serving to accelerate the construction of ADUs of all types. Thus, the dower house, or granny flat, with its ancient roots, holds promise and challenges for today’s older adults.

A Convergence of Advocacies: Granny Flats and the Missing Middle

The landmark 1926 Euclid v. Ambler Realty ruling that established the enabling legal basis for zoning was partly a referendum on the social value of dense living. Justice George Sutherland stated in his Ambler opinion, “Very often the apartment house is a mere parasite,” bringing “disturbing noises incident to increased traffic and business” and “depriving children of the privilege of quiet and open spaces for play” (Village of Euclid v. Ambler Realty Co., 1926). This early 20th century bias against apartment-dwelling, combined with the mid-century need to house returning WWII veterans, meant that the legal regulations in the majority of American communities governed what could be built and almost exclusively favored the single family home.

By the late 1990s, however, as a granny flat revival was being proposed as an alternative housing aging arrangement for older people, the Smart Growth and New Urban movements had begun to develop popular interest in returning to more diverse, compact, mixed-use “Traditional Neighborhood Development” patterns (National League of Cities, 2017). New Urbanists recognized that the 20th-century bifurcation of housing stock into single and multifamily use categories had wiped out a wide range of housing that existed in between those two categories.

The New Urbanists identified these disappearing types as “The Missing Middle,” which included everything from duplexes, to quads, to cottage courts, all the way up to small-scale multifamily complexes of ten to thirty apartments (Missing Middle Housing, 2020). All of these housing types were disappearing from the urban fabric, and missing-middle advocates argued for their return because of the economic and life-stage diversity they brought to a community. The coalescing of granny flat–caregiving advocacy and missing-middle advocacy meant that smaller units located on existing properties were again being considered as solutions to housing, financial, and-or concerns around aging.

Convergence with the Tiny Homes Movement

A second movement that has supplied additional energy and attention to the granny flat model is the tiny house. Since their introduction, tiny homes have generated wide appeal as affordable housing (often for young adults) and have driven local ADU policy change (, 2020).

Tiny homes are overcoming many of the previous objections to ADUs by emphasizing modern design, tapping into growing societal concerns around housing affordability, and embodying environmental sustainability. The tiny home has a different brand and “sexier” curb appeal, but in reality can function in the same way the granny flat always has. Tiny homes are continually featured in high-design magazines, and have become associated with more sustainable mode of living that leaves a smaller environmental footprint.

While granny flats were hampered for decades by zoning regulations prohibiting their construction, tiny homes began to pick up momentum in the early part of the 21st century by avoiding some of these regulations altogether. Tiny homes often are built on a trailer chassis with wheels. When they are not permanently affixed to the ground, their construction does not require a building permit; instead, they are licensed by departments of motor vehicles as travel trailers. Tiny homes usually are built with heavier duty house materials, such as two-by-fours, lap siding, and drywall, and prioritize the needs of daily living in one place, as opposed to the lightweight weekend mobility of the tiny home predecessor, the camper trailer.

Legalizing accessory dwelling units is one strategy local communities are using to increase supply.

Legally viewed as trailers, zoning often permits storing tiny homes on single-family home properties, but prohibits their occupation when stored. However, as communities are trying to diversify their housing stock, often it is easier politically to be lax in enforcing occupancy restrictions to a tiny home parked on a residential lot than it is to alter single-family zoning to allow for ADUs.

Quite the opposite of a granny flat for a frail parent, the tiny home taps into the appeal of recreational vehicles, aka RVs, as a return to a more carefree way of living. This lifestyle appeals especially to young hipsters or active empty nesters, and is an upscale version of the VW microbus—with better amenities. The association with carefree adventure that comes with attaching the house to wheels orients this housing type away from associations with frailty and a need for care, toward smaller, simpler, and easier living.

As tiny homes have grown in popularity and captured the imagination of a broader group of people, more and more communities have adopted policies that allow ADUs (whether they are called granny flats or tiny houses). This moves tiny homes off the trailer category, out of the regulatory jurisdiction of the Department of Motor Vehicles, and into the realm of more common building and zoning practices.

Convergence with the Affordability Crisis

As the housing affordability crisis has spread from just a few coastal urban centers to almost every major metropolitan district in the country, and as federal housing subsidies have shrunk, communities have been looking for local solutions. While affordability has long been a problem in places like New York City, San Francisco, Los Angeles, and Washington, D.C., communities emerging from the most recent recession are experiencing a significant rise in housing prices and rental rates. Housing construction has slowed and is not keeping pace with population growth, restricting supply and driving up prices (Joint Center for Housing Studies of Harvard University, 2019). Now cities like Austin (Texas), Raleigh and Charlotte (North Carolina), Atlanta, Chicago, and Philadelphia are finding their longtime residents priced out and their new residents unable to live within a reasonable commuting distance of their jobs.

Legalizing ADUs is one strategy local communities are using to increase supply. By providing smaller and less expensive units within existing neighborhoods, local communities hope to increase housing supply without building extensive and costly new infrastructure. In these scenarios, ADUs are envisioned for young adults and newly formed households without children, or for singles. They are framed as viable options for the retail and service industry workforces, populations that often are priced out of any housing.

Most of the changes in rules and regulations that have made ADUs easier to construct have much more to do with increasing housing supply than with caring for older people as they age. Nonetheless, these changes have increased the feasibility and availability of granny flats in far more communities than was the case twenty years ago.

Convergence with Mom and Pop and Multifamily Dwellings

As the supply of affordable housing shrinks, strategies have broadened beyond increasing housing supply and housing subsidies to consider how housing can be made affordable by its potential to generate income. Approached in this way, smaller housing units on the property of an existing homeowner (the same type of housing needed for granny flats) are being welcomed into existing neighborhoods. Using rental housing as a source of supplementary income is a return to a once common practice involving “Mom and Pop,” or “multifamily” dwellings.

Prior to the post WWII housing boom, families built low-density housing for other families. It was common for immigrant families to gain a foothold in the American economy by constructing a two-, three- or four-family home (i.e., duplex, tri-plex, or quadruplex). They would live in one unit, and derive income by renting out the other(s). At these scales of production, small rental developments of two to as many as thirty units flourished and created the category of multifamily residences.

After WWII, housing production was industrialized by large developers such as Levitt & Sons, often using factory assembly methods developed while building WWII troop barracks. Multi-family homes began to disappear from the housing stock, a trend that was exacerbated as the Federal Housing Administration encouraged single-family home production, while institutional, syndicated financing encouraged the production of developments larger than thirty units. Lost were the small multifamily homes that could create affordability for the family that owned one unit and the families that rented the other units. As housing types that supported two to three households living on a single property began to fall out of favor, so, too, did the acceptance of and the policy and financing for ACUs and granny-flat living.

Fast forward ten years into the 21st century, as new online services are reintroducing the concept of multiple households on a single property. These services are reviving the old idea of individual owners becoming small-scale landlords by renting out units on the same property where they live. The rise of Web platforms like VRBO and Airbnb have made it possible for many to consider turning their properties, or part of their properties, into income-generating opportunities. Through these services, unrelated individuals or households live on the same property in short- and (increasingly) long-term arrangements.

As more older adults look for opportunities beyond their 401(k)s or shrinking pensions to accumulate retirement savings, these new services have put rental income within reach of many more people. Many families, including younger retirees, are building apartments into their homes or constructing ACUs to supplement income (Edgar, 2018). As a result, Mom and Pop rental arrangements are rapidly returning, and with them a growing interest in policies and financing that support ADUs, granny flats, and the duplexes, triplexes, and quadruplexes of the past.

While this new online technology is increasing the number of rental units available on owner-occupied properties and creating smaller housing units within existing neighborhoods—both defining criteria of the granny flat—they have proliferated at such a rate that many communities are struggling to accommodate the change. Some community advocates think that as units are listed with these online services, this removes housing from local stock, thereby driving up costs. As a result, some new local regulations are limiting certain rental arrangements in order to curb the use of local housing stock in this way. So, while these services may have made it easier to rent out a smaller apartment on an owner’s property, backlash could reintroduce regulations, and, once more, make granny flats illegal.

Not Your Grandmother’s Granny Flat

The advent of ADUs has successfully led efforts to diversify the housing stock in many low-density suburban neighborhoods across the nation. Initially, ADUs were welcomed, in part because they met a need for older adults, who are an important political constituency and who often want to remain in their community or live near their families. In opening up more living arrangements for older adults, granny flats have uncovered the significant market of childless households whose residents do not need or want an expansive three-bedroom–two-and-a-half-bath home, no matter the residents’ ages. These new and expanding uses of the ADU have gone far beyond the dower house to serve many different needs in a community and have made ADUs more popular than ever.

Building on recent success, the future offers an opportunity to return to the ADU type and ask how it might be further tailored to older adults’ needs. The most significant opportunity would be to look at the “A” in ADU. Codes define “accessory” as a subsidiary building, diminutive to and usually tucked behind the primary structure. This deference does not always reflect the economic standing or social needs of older adults. With increasing demand for smaller units in more urbanized environments, the granny flat may be better deployed as one or more buildings lined along the property frontage; this arrangement could help to shape, activate, and passively supervise street life much more effectively than a deep front yard.

‘The United States has an opportunity to ensure that the “flat” is still available and well-suited to the “granny.” ’

Lose the “accessory” designation, and small cottages and-or townhomes could play a significant role in retrofitting suburbia for more pedestrian- and public realm–oriented living; these types of dwellings could be deployed either as liners that urbanize the frontage or they could be pulled up alongside properties’ existing homes where large side yards isolates neighbors from each other. In low-density, big-lot neighborhoods with homes pulled way back from the street and buffered from each other by spacious side yards, many older adults might consider leading the effort to urbanize suburban streets.

The granny pods of the 1990s provided an extension of care to the suburban fabric, and in doing so helped to make the ADU type more palatable to suburban communities. As ADUs and other smaller living arrangements have gained interest and availability, the United States has an opportunity to ensure that the “flat” is still available and well-suited to the “granny.” No longer a version of the suburbanized dower house behind a manor, replacing the “A” with a “U”—renaming this housing type as the “Urban Dwelling Unit”—could plant the flag for older adults who would rather be part of reshaping communities for the 21st century instead of being shoehorned into communities built around the social and economic relationships of the mid-20th century.

M. Scott Ball is principal at Commons Planning, in Atlanta, Georgia. Kathryn Lawler, M.A., is executive director at the Atlanta Regional Collaborative for Health Improvement.

Pictured at top: An example of a duplex ADU/Granny Flat. Image courtesy of M. Scott Ball.


272 U.S. 365, Village of Euclid v. Ambler Realty Co. (No. 31), November 22, 1926. 2020. Retrieved March 20, 2020.

Edgar, J. 2018. “Opinion: Thinking of Being a Landlord in Retirement? These Tools Could Make it Easier.” MarketWatch. Retrieved March 20, 2020.

Joint Center for Housing Studies of Harvard University. 2019. “The State of the Nation’s Housing 2019.” Retrieved March 20, 2020.

Missing Middle Housing. 2020. Retrieved March 20, 2020.

National League of Cities. 2017. “Traditional Neighborhood Development.” Retrieved March 20, 2020.