A Scalable Housing Solution: Embracing ADUs in an Aging, Low-Growth City

Introduction: Reimagining Housing for an Aging and Economically Shifting City

Detroit is at a crossroads, facing demographic change, economic restructuring, and the long shadow of its twentieth-century urban form. One pressing question currently facing city officials and planners is how to house Detroit’s growing senior population in a way that is financially sustainable, socially equitable, and compatible with the city’s future land use goals. In this context, accessory dwelling units (ADUs) have emerged as a potentially transformative tool. These small, single-story, energy-efficient homes could provide aging Detroiters with housing better suited to their physical, economic, and social conditions, while also advancing broader goals related to neighborhood revitalization, zoning modernization, and population stabilization.

The issue of senior housing came into focus during a recent community meeting hosted by the City of Detroit Planning Department, where participants reviewed materials from the new master plan initiative. In a section titled “More Housing Choices in Neighborhoods,” the city floated proposals to adopt an ADU and missing middle pattern book, allowing for a broader range of permitted housing typologies. Group discussion at my table quickly turned to the lived experiences of the senior residents in attendance. Many of them spoke candidly about struggling to maintain aging homes that were no longer suitable for their physical needs or household sizes. One participant noted the need for single-level homes, while others called for better accessibility retrofits. Many shared stories of deferred maintenance they could not afford to address.

These testimonies reflect a citywide trend. As household sizes shrink and the population continues to age, Detroit must now grapple with the implications of its oversized housing stock. The question is not merely how to build more housing, but how to build the right kind of housing for the residents who need it most. ADUs may offer a powerful solution, but only if planned and deployed thoughtfully, in coordination with long-term goals around land use, equity, economic development, and neighborhood sustainability.

The city of Detroit, like many other places, is experiencing shrinking household sizes, a rapidly aging population, and a deep need for new cost-effective housing construction. We should consider the case for ADUs and their efficacy as a housing solution to issues facing the city. If we care about aging in place, housing equity, and sustainable revitalization, ADUs are a solution worth examination.

Household Size and the Death of the Single-Family Home Neighborhood

Mass migration out of the city isn’t the only thing shaping Detroit’s modern housing crisis, household size has collapsed as well. Nationally, the average household shrank from 3.3 people in 1960 to about 2.5 today. In Detroit, that figure is even lower. According to 2022 American Community Survey data, the average household size in Detroit is just 2.4 people (QuickFacts: Detroit City, Michigan, 2024). This matters more than it seems. Detroit was built for larger, often multi-generational households. Those homes still exist, but they are now occupied by single individuals or elderly couples, leading to underutilization, unnecessary utility costs, and burdensome maintenance expenses.

A comment on a recent LinkedIn post of mine underscored this point: “…Recent pricing in places like Detroit can seem nonsensical at first look because of their lack of population growth, yet when you dive deeper into the data, an aging population can still increase demand due to increased household formation, even if the population remains flat.” In short, fewer people are living in each home, but each person still needs a home. Housing demand doesn’t disappear just because the population isn’t growing. This reality intersects with my own working theory, which I shared on social media: “Detroit’s proliferation of single-family homes made more sense when average household sizes were larger. Now, in today’s day of two or single-person households, neighborhoods of exclusively single-family homes will obviously struggle, whereas neighborhoods comprised of varied configurations are visibly more vibrant and habitable.”

So we arrive at a paradox: Detroit’s population growth is slow, but its need for smaller, more affordable housing, continues to rise.

The Reality for Seniors: Aging on Fixed Incomes

My current work interning for a Detroit City Council member has put me in direct contact with the people behind these statistics. I’ve repeatedly seen how seniors advocate for housing assistance during the council member’s office hours and at public forums. Most are lifelong Detroiters, having raised families and contributed to the city’s fabric for decades. But they are aging in old homes, many built between 1920 and 1940, that now require major repairs, costly refitting, and ongoing upkeep that far exceeds what a retiree living on a fixed income can afford.

Their concerns fall into a few major categories:

• The need for home repairs like roof and porch repairs or insulation improvements.
• Needed safety retrofits like railings, bathtub seating, or stair lifts.
• The desire for smaller, single-level homes due to mobility issues.
• Difficulty with upkeep and maintenance and a repeated ask for financial assistance for home repairs.

The majority of the homes in Detroit were built nearly a century ago and require not just minor repairs, but often major structural updates. The city’s Housing and Revitalization Department (HRD) does offer some support for repairs, but resources are limited. The number of seniors needing assistance far exceeds the available funding. Home repair is expensive, and spreading limited funds across a sprawling, aging housing stock is not sustainable.

Detroit’s aging population is neither an accident nor a temporary anomaly. It is the result of deep structural forces, including a legacy of disinvestment, population loss, and a housing stock disproportionately composed of detached single-family homes. These are the people who have lived in the city for decades, remained loyal to a city with a dwindling population while neighborhoods crumbled around them, reached old age in that city, and live in old homes that were here even before they were. It should not be surprising that such aged homes are in need of major repairs. 

According to 2024 Census data, over 16 percent of Detroit residents are now over the age of 60. More than 55,000 households in the city are headed by someone 65 or older (QuickFacts: Detroit City, Michigan, 2024). Along with the parallel demographic trend of shrinking household size, the data reflects a widespread mismatch between people’s needs and the homes they inhabit.

The Case for ADUs in an Aging, Low-Growth City

Accessory dwelling units offer an alternative that could simultaneously address the needs of seniors and the city’s broader land use challenges. Properly implemented, ADUs can provide aging residents with smaller, more manageable homes that better match their current lifestyles and budgets, while also adding density and tax base to neighborhoods that have suffered from population loss.

Accessory dwelling units (ADUs) are small, single-family homes typically under 800 square feet, built either on the same lot as a primary residence or as standalone infill on vacant parcels. In cities that have embraced ADUs like Portland, Los Angeles, and Austin, they serve as a flexible, lower-cost housing solution with a range of social and economic benefits.

For Detroit, here’s why ADUs make particular sense for seniors:

• Lower Cost and Maintenance: The cost of retrofitting an old house to meet senior needs can be prohibitive, both for the homeowner and for public programs subsidizing repairs. ADUs are cheaper to heat, cool, and maintain than century-old homes. A senior moving into a new, efficient unit might save hundreds per month in energy costs alone.
• Aging in Place: ADUs can be mass-produced and designed with universal accessibility standards in mind, meaning no-step entries, single-story layouts, walk-in and seated showers, grab bars, and wider doorways. These features enhance safety and reduce the risk of falls, the number one cause of injury among seniors, and mean that seniors can stay in their community without staying in a home that no longer fits their needs.
• Community Support: Seniors living in clusters of ADUs can maintain social ties, reduce isolation, and share caregiving or transportation services, especially if placed near transit, grocery stores, or health facilities. 
• Intergenerational Housing: ADUs allow seniors to live near family without cohabiting. A backyard cottage could house a parent, while adult children live in the primary home—or vice versa. When built behind or beside existing homes, ADUs allow seniors to live near children, family caregivers, or neighbors, and remain in their beloved neighborhoods. This proximity can delay or prevent the need for assisted living, lowering public healthcare costs and improving quality of life.
• Community Vitality:
By clustering small homes in walkable, transit-connected neighborhoods, the city can increase density without sacrificing neighborhood character. ADUs diversify the housing stock while preserving the scale of low-rise residential streets, yet helping neighborhoods remain vibrant and intergenerational.

ADUs as a Strategic, Scalable, and Sustainable Solution 

ADU implementation can be planned strategically to align with neighborhood revitalization goals. Because they can be built on vacant lots or as additions to existing homes, they represent a “gentle density” tool: a way to incrementally increase population without requiring large-scale demolition or large-footprint development. With nearly 19 square miles of vacant land across the city Detroit has no shortage of potential infill sites where ADUs could be deployed to help re-knit the urban fabric, especially in areas where infrastructure still exists but population has thinned (Huffman, 2022).

A 2025 report published by the Detroit Land Bank Authority states that there are currently over 59,000 vacant lots in their inventory, but that doesn’t mean we should scatter ADUs randomly (2025 Second Quarter Report, n.d.). We need criteria to determine where they make the most impact and how to balance ADU development with other housing strategies like multifamily infill. To realize the full potential of ADUs for Detroit’s seniors and other vulnerable groups, we must be strategic about placement. Here are some guiding principles for where ADUs should be prioritized:

• Neighborhood Typology: Target neighborhoods with relatively stable infrastructure, existing community engagement, and low rates of violent crime. ADUs thrive where people feel safe and where there’s already some existing density. ADUs make the most sense in neighborhoods that are stable or transitioning, not those that are entirely depopulated or plagued by extreme blight. These areas would already have some residential fabric to support walkability and social cohesion but could benefit from gentle density. In vacancy-heavy areas where large swaths of land sit unused, ADUs could be clustered into small, walkable micro-communities using vacant parcels acquired by the land bank. These “ADU villages” could be pre-permitted and pre-designed to reduce cost, supported by nonprofit housing developers or modular construction firms.
• Walkability and Transit: Seniors are less likely to drive. ADUs should be placed near bus routes, grocery stores, clinics, and community centers. Streets with existing sewer, water, electricity, and transit access can accommodate ADUs more efficiently and at lower public cost. Areas with good transit or future transit investments should be prioritized to reduce car dependency among seniors.
• Parcel Characteristics:
Vacant side lots or oversized lots with rear access are prime candidates. These allow for infill construction without altering the rhythm of the street.
• Zoning Flexibility:
Areas where upzoning or form-based codes can be implemented easily should be prioritized to streamline permitting. A future zoning code that includes an ADU and Missing Middle Pattern Book can help reduce approval times and developer uncertainty.
• Avoiding Displacement Pressure: ADUs should be used to increase housing supply and affordability in neighborhoods at risk of becoming exclusionary. These growth corridors are also ideal for integrated development strategies where transit, housing, and services can be coordinated.
• Complementing, Not Replacing, Multifamily Development: Some neighborhoods are better suited for larger infill like duplexes or fourplexes. ADUs work well as gentle density tools in areas that may not have the space to accommodate larger-footprint development.

Think of it as a spectrum: neighborhoods with high vacancy and underbuilt infrastructure are better served by large-scale reinvestment and multifamily housing, while stable areas with excess land can benefit from gradual densification through ADUs.

A large part of the strategy around ADU placement needs to also make space for a conversation about how to find the right mix of ADUs and multifamily development to support the housing needs of current Detroiters as well as future Detroiters. Future plans should be crafted with an eye to sustainable land use planning, aimed at supporting a growing population, age diversity, income diversity, and revitalized neighborhoods comprised of diverse household configurations. Sustained rejuvenation occurs when cities accommodate the needs of all age cohorts. These needs include housing and social interconnection, among others. We always hope that the strategies implemented today result in a more robust economy and prosperous citizenry. We need to think long term about how plans set today affect our city tomorrow.

Beyond Seniors: A Broader Housing Equity Vision

Though this essay centers on seniors, ADUs are not a solution only for seniors. Their affordability and scale make them useful for:

• College students
• Low-income workers
• Disabled residents
• Young adults entering the housing market
• Unhoused individuals transitioning into permanent supportive housing

Some cities provide vouchers or financing to help these populations rent or build ADUs. Detroit could pilot demand-side interventions, using vouchers or grants for seniors or others to construct or move into ADUs, potentially offsetting costs and reducing the need for more expensive alternatives like institutional care or emergency shelters. Whether vouchers are required to subsidize rent or ownership depends on the financing model and household income levels, but integrating demand-side subsidies like housing vouchers or local assistance programs can help increase adoption.

Reimagining the Neighborhood: Aesthetics and Urban Form

A Detroit with ADUs isn’t just more affordable, it’s more vibrant. Imagine walkable streets lined with old brick homes interspersed with new, small-scale homes located on formerly vacant lots. Imagine previously grim neighborhoods made vibrant once again because strategic planning allowed housing to be built cheaply and quickly, increasing population density to levels not seen in decades.

While ADUs are technically single-family homes, the neighborhoods they help create are more dense, more intergenerational, more connected, and more flexible. With intentional design, clusters of ADUs can form micro-villages within the city, maintaining Detroit’s green, open feel while introducing more walkable nodes of social and commercial life. These neighborhoods could feature shared courtyards, green space, and other urban design elements—fostering intergenerational interaction and place-based identity.

As some seniors opt to move into ADUs, their former homes may become vacant. Instead of leaving them to deteriorate, an interesting densification strategy would be to redevelop these properties into duplexes, triplexes, or fourplexes, housing typologies that better reflect contemporary demand. Over time, Detroit could transition from neighborhoods dominated by aging single-family homes to mixed-density residential districts that accommodate a more economically and generationally diverse population. This transition has long-term fiscal and planning benefits:

• Higher property tax revenue per acre.
• Lower per-capita infrastructure costs.
• Increased transit ridership potential.
• Stronger local economies due to population retention and attraction.

It’s imperative to build a planning framework that is self-reinforcing. That requires coordinating zoning reform, housing development, transit investment, and infrastructure upgrades in ways that expand the city’s tax base while meeting real human needs.

Fiscal Strategy and Policy Considerations

When considering whether to invest public dollars in ADU construction or senior home repair, the city must weigh long-term return on investment. While a home repair grant may extend the viability of an old home for a few more years, it does not alter the fundamental mismatch between household size, size of the home, and physical functionality. By contrast, ADUs can yield a more sustainable asset that serves current and future populations. In comparison to these aged homes, ADUs would be easier to maintain, more energy-efficient, and more adaptable to future needs. If sited strategically, they would also contribute to local tax base growth, increase population density, and attract additional investment.

Of course, no housing intervention is without trade-offs or challenges. ADUs, while elegant in theory, require enabling regulatory frameworks, site-specific infrastructure readiness, and sustained political support. Many neighborhoods in Detroit still enforce restrictive zoning codes that prohibit more than one dwelling per lot or mandate excessive setbacks and off-street parking requirements. Permitting processes can be opaque and inconsistent. Sewer and water hookups can be cost-prohibitive or technically unfeasible on narrow lots.

There is also the cultural barrier. Some residents view ADUs as an intrusion on neighborhood character, worrying about noise, crowding, or the “backyard rental” effect. There is also a risk that informal ADUs built without permits or proper inspections could proliferate if the legal pathway remains costly or confusing.

Cities such as Minneapolis, Seattle, and Austin offer useful case studies in how to overcome these barriers. Minneapolis adopted a form-based code that permits ADUs by right in all residential zones. Seattle created a dedicated ADU permitting help desk and eliminated off-street parking requirements. Austin launched a publicly funded ADU blueprint library to standardize design and reduce costs. These examples can be instructive as Detroit plans its own ADU development strategy.

The most effective ADU strategy will be one that links individual housing needs with long-term systems change. To that end, Detroit should:

• Legalize ADUs by right in all residential zones, using a combination of form-based zoning and overlay districts. 
• Create a permanent ADU permitting office staffed with planning and design professionals to provide guidance to homeowners. 
• Pair ADU development with senior relocation incentives that offer financial support and logistical help. 
• Use modular construction firms or community workforce programs to lower unit costs and create jobs.
• And finally, integrate ADU planning with broader goals around transit access, health services, and economic mobility.

Final Thoughts: A Smart City Plans for the Future, Not the Past

Detroit’s aging population deserves better than to be locked into homes that are no longer safe, comfortable, or affordable. The city recognizes this, but recognition alone isn’t enough. We need clear zoning reforms to legalize ADUs across neighborhoods. We need financial tools to help seniors build or move into them. We need infrastructure investment to support their placement. And above all, we need a unified vision of a Detroit where people of all ages and incomes can find a home that fits their needs. Revitalization isn’t just about new buildings. It’s about making sure the people who stuck with this city through thick and thin can live, thrive, and age in dignity. ADUs are a tool to do exactly that.

Detroit’s senior housing dilemma reflects a deeper truth about post-industrial American cities. The future cannot be built on antiquated housing models incompatible with the world we want to live in. We must recognize that shrinking household sizes, aging infrastructure, and shifting demographics demand a new approach. Accessory Dwelling Units are not a universal solution, but they are a tool in a diverse portfolio of typologies meant to address distinct housing needs in a broader urban revitalization strategy.

If designed and deployed well, ADUs can help Detroit transition from a pattern of heavily vacated, underused, and increasingly obsolete homes to a new landscape of accessible, intergenerational, walkable neighborhoods. In doing so, they may also serve as a model for how legacy cities across the country can adapt their aging 20^th-century housing stock to meet the needs of the 21^st century and beyond.

References

City of Detroit Planning Department. “Possibilities Overview: Master Plan Engagement Draft,” 2024.

QuickFacts: Detroit city, Michigan. (2024). Census Bureau QuickFacts; United States Census Bureau. https://www.census.gov/quickfacts/fact/table/detroitcitymichigan/PST120224#qf-flag-X

Huffman, B. (2022, September 27). Detroit has plenty of land. Do residents have equal access? BridgeDetroit. https://www.bridgedetroit.com/detroit-has-plenty-of-land-do-residents-have-equal-access/

2025 Second Quarter Report. (n.d.). Detroit Land Bank Authority. https://dlba-production-bucket.s3.us-east-2.amazonaws.com/City_Council_Quarterly_Report/DLBA+Q2+FY25+City+Council+Quarterly+Report.pdf+(2).pdf

Chapple, Karen. Planning Sustainable Cities and Regions: Towards More Equitable Development. Routledge, 2014.

Mallach, Alan. The Divided City: Poverty and Prosperity in Urban America. Island Press, 2018.

HUD. “Accessory Dwelling Units: Case Studies and Policy Guidance.” U.S. Department of Housing and Urban Development, 2021.

AARP. “Making Room: Housing for a Changing America.” 2019