July 25, 2022
Elimination of single-family-only zoning is quickly gaining currency in Minnesota, Oregon, and other places across the country. This innovation disrupts conventionally segregated land use by allowing multifamily structures by right in any residential zone, which advocates argue can help promote housing affordability and diversity.
Despite much debate over these measures, curiously little attention has been paid to the legal context — or perhaps not so curiously, as the 1926 U.S. Supreme Court decision constitutionally authorizing comprehensive zoning has never been revisited. That decision, Euclid v. Ambler, ruled that segregating land uses through zoning is a valid exercise of police power — or the government's power to control its jurisdiction in the interest of general security, health, safety, morals, and welfare — because it protects residential areas from the supposed dangers of mixed uses.
Almost 100 years later, modern planners might see little point in consulting other legal reasoning of the era. To be sure, zoning was upheld by most judges, even before the Supreme Court made Euclid the law of the land.
But a cadre of state supreme court opinions issued before 1926 took a different tack, concluding that shielding single-family neighborhoods from other uses is often discriminatory and, essentially, unconstitutional. This small group of cases offers arguments against the legal legitimacy of exclusionary zoning that can be useful in today's policy debates.
Legally questionable justifications
Euclid's value to municipalities is in its declaration that comprehensive zoning does not amount to regulatory taking (a governmental regulation that limits the use of private property depriving it of its economic value), thus freeing cities from the need to compensate property owners. That logic is grounded in many legally meaningful aspects of zoning, but especially its alleged power to prevent harm, thereby passing the crucial test of any regulatory policy legitimized by the police power: to protect some aspect of the public welfare.
Yet that was the rub in cases where a state supreme court overturned a comprehensive or rudimentary zoning effort. Judges did not see a valid public welfare justification for separating single-family from multifamily or low-intensity commercial uses. What they did see, however, was evidence of bias, discrimination, and legally questionable justifications.
Many of these cases revolved around disputed attempts to ban multifamily structures in single-family detached residential (SFR) neighborhoods, with the courts finding regulatory justifications weak or nonexistent. In 1917, for example, the Minnesota Supreme Court prohibited an effort in Minneapolis to reject a four-unit building on the assumption of "nuisances" like congestion, crime, and fire risks. Similarly, the Maryland Supreme Court in 1916 confronted a state law (passed at the behest of homeowners) prohibiting apartments in a Baltimore neighborhood. In overturning the statute, the ruling challenged the putative harms like the alleged fire hazard — existing homes were constructed of wood, it pointed out, while the proposed apartments were to be brick.
The approach these judges took suggests single-family-only zoning may not just be bad policy, but constitutionally deficient, too.
Later, in 1922, the New Jersey Supreme Court rejected the exclusion of a two-family home in a SFR neighborhood because the city of South Orange had jumped straight to prohibition. If there were a legitimate public harm, the opinion questioned why it hadn't been managed with a new condition, like a building setback. The real motivation for refusal seemed obvious to the justices: Neighbors simply did not want a multifamily building there.
One year later, that same court restricted application of a similar ordinance in Nutley, which attempted justification via blight avoidance. The court observed that, in reality, the "blight" concern was a fear of people of different nationalities, ethnicities, and races moving into the area. The opinion declared that assessment unreasonable and discriminatory.
Other decisions of this era overturned prohibitions on small stores in neighborhoods. Justices typically explained that it was appropriate to limit retail operations that could impact public welfare through dangerous substances or manufacturing processes. But banning trade in goods that would not spoil, explode, attract vermin, or so on, failed the basic test. A characteristic ruling from the Colorado Supreme Court in 1913 found that Denver's prohibition of a proposed store that met all building specifications did not "to the slightest degree have any relation to health, safety, welfare."
Police power and zoning
From a policy perspective, these ideas are not new; planners have long challenged the logic of Euclidean zoning. But that generally led to adoption of mixed-use zoning as an alternative to segregated zones, not a substitution, leaving the legal foundation of single-family exclusivity in place. In other words: Planners were free to innovate, but where cities opted to retain conventional zoning, its legal foundations remained rock solid.
Zoning retains legitimacy today despite a growing recognition that it does not strictly align with the police power — scale-appropriate multifamily and neighborhood commercial uses rarely represent material threats to single-family homes. This has largely been glossed over because zoning (theoretically) emanates from a comprehensive plan, indicating public support, a lack of arbitrariness, and generic (if not specific) links to public welfare.
But the approach these 20th-century judges took when encountering SFR zoning for the first time suggests it may not just be bad policy, but constitutionally deficient, too. A key takeaway is reconsideration of police power justifications that only protect the preferences of existing homeowners. These judges articulated that idea through "aesthetics," a term they applied to uses that presented no physical danger or discomfort but were repugnant to residents simply by their nature.
This assertion, that police power fails to justify SFR zoning, is due for a revival. While policy experts are successfully advocating for the advantages of zoning reform in many communities, this legal argument goes further by weakening the foundational legitimacy of exclusionary zoning.