The (House) Key to Affordability and Access: Gentle Density and Missing Middle Housing in New Jersey

New Jersey is the most densely populated state in the US. However, the state is enduring a crisis of housing affordability and accessibility. From 2023 to 2024, the median home price rose by 10.8%, compared to just a 4.3% rise in the average salary. There is a shortage of over 205,000 affordable homes for extremely low-income renters, and more than half of renters are cost-burdened, dedicating over 30% of their income to housing. Much of this scarcity stems from restrictive zoning regulations that municipal governments dictate. This exclusionary system chronically underproduces housing despite high market demand, as existing residents rally against multi-family housing as a threat to town character, property values, and traffic. This “Not in My Backyard,” or “NIMBYism,” helps produce the single-family detached housing model that dominates New Jersey’s housing market at 53% of total housing supply. Further, in nearly half of New Jersey municipalities, over 70% of housing is single-family detached.

Single-family homes became the American norm following World Wars I and II, spurred by the proliferation of cars and the provision of generous government benefits that encouraged home ownership. However, with rising housing costs and mounting climate concerns, this model no longer addresses the needs of many Americans. Although New Jersey’s Mount Laurel Doctrine creates a constitutional mandate requiring each town to provide its “fair share” of affordable housing, the policy targets housing for households with low or very low incomes. As in many areas of American life, middle-income families slip through the cracks. “Missing middle” housing — “[m]edium-density multi-family housing that is compatible in scale with single-family or transitional neighborhoods” — could help to fill this glaring gap. 

Missing middle housing includes forms of high-density housing, such as duplexes, triplexes, cluster homes, and accessory dwelling units, all of which are gaining popularity nationwide. As these “gentle density” models fit more seamlessly into the aesthetic and structure of predominantly single-family communities than high-density apartment buildings, they may be less likely to face NIMBY backlash.

Middle housing does, however, come with many of the benefits of traditional high-density housing. New Jersey is a major commuter state, with one of the largest public transportation systems in the nation. Fully utilizing this infrastructure means maximizing ridership, which requires increasing access to transit stations. However, nearly half of New Jersey transit stations are surrounded by more single-family detached housing than the state average of 53%, limiting access to public transportation and tilting existing access towards higher-income households.

Demand for housing near public transportation is high, but restrictive zoning practices interfere with the development of density surrounding transit hubs — 61% of the areas surrounding transit stations either severely limit or prohibit the development of multifamily buildings. As access to public transportation facilitates the attainment of higher-paying jobs, the exclusion of lower-income households from transit-rich areas systemically perpetuates income inequalities.

Gentle density multifamily housing also reduces the carbon footprint of each household, limiting the amount of unused space requiring climate control and mitigating emissions from driving. Further, it offers options for a wide range of populations, including multigenerational housing for older adults hoping to live near family, “starter homes” for young families, independent but proximate living for those with disabilities, and non-family households for the increasing number of Americans choosing not to have children.

For all New Jersey families to reap the benefits of missing middle housing, municipalities must lift restrictive single-family zoning regulations. New Jersey could follow the lead of states including California and Maine, which have eliminated single-family-only housing mandates. In fact, New Jersey already has a model for the successful implementation of gentle density housing: Palisades Park. This municipality has permitted double-family homes since its first zoning ordinance in 1939, a policy unique to its region in Bergen County. While single-family homes initially predominated, rising demand in the 1990s and 2000s led to infill development, and now just 21% of housing stock is single-family detached. 

With this growth in density came a host of economic advantages. Palisade Park’s population has grown by 154% since its original zoning ordinance, surpassing all its surrounding boroughs. The density of residents has fostered a thriving commercial sector, reduced residential and commercial property taxes, and generated greater land value per acre than the majority of surrounding boroughs. Compared to the neighboring borough of Leonia, Palisades Park enjoys lower property taxes, higher commercial property values, and triple the commercial square footage and commercial property tax revenue. 

Palisades Park should serve as a model for the rest of New Jersey of what inclusive housing policy can achieve. Removing barriers to gentle density and middle housing could be the key to unlocking affordability and access in the state’s housing market.