Zoning regulations have lately come under fire for making cities less dense and driving up the cost of new homes. State legislatures are increasingly responding by preempting aspects of local zoning authority. But despite its real problems, both now and historically, local zoning power remains an important tool among cities’ limited set of options for adapting to climate change. To avoid hamstringing local governments that are trying to implement climate adaptation measures, legislatures should recognize that local zoning authority is a critical tool to adapt to climate change and, as a result, be cautious in how they go about restricting municipalities’ power to shape the built environment. This blog post offers three key recommendations for states to support denser city development while still preserving local governments’ authority to response to climate change.

One Hundred Years of Euclid

A century ago the Supreme Court confirmed in Village of Euclid v. Ambler Realty Company that local governments’ police power generally permits them to limit the uses to which land in the city could be put. That decision opened the door to the ubiquitous, color-coded maps that broadly separate cities into residential, commercial, and industrial zones, as well as dozens (or more) of subspecies of each. Cities set strict rules for how land in each zone can be used.

Critics are now taking particular issue with single-family residential zones—ones that dominate the American landscape and that archetypically require large lot sizes and major setbacks from lot boundaries (among other things), and that only admit exceptions to their detailed rules after lengthy, uncertain review processes. Critics argue that minimum lot sizes reduce the number of homes that can be constructed and drive up the cost of ones that are built; that discretionary approval processes give “Not In My Backyard” (NIMBY) interests too much power to quash development that would be good for the community at large; and that a collection of other rules dictating setbacks from streets, open or permeable space requirements, and height limits are making development slower, more expensive, and worse for the climate.

With the costs of housing skyrocketing and homeownership on the decline, especially for younger people, elected officials at every level of government are understandably looking for solutions to these problems. For many state officials, restricting local government’s zoning authority looks attractive, but it could backfire if not done carefully.

A Highly Prescriptive Legislative Response

For several years now, state legislatures across the political spectrum have been introducing legislation to try to tackle some of the problems associated with single-family residential zones by preempting local control over aspects of zoning. The trend has continued into the current session and, as several examples highlight, state legislatures are considering highly granular rules for how cities regulate zoning:

• A “Housing Readiness Package” of bills in Michigan includes HB 5530, which seeks to rein in local authority under the state’s zoning enabling act. If passed, the bill would specify that a zoning ordinance adopted by any local government in the state “must not impose a minimum parcel size of more than 1,500 square feet on land zoned for a detached single-family residence if the parcel is accessible to and will be served by public water and public sewer.” A related bill in the same package, HB 5583, would cap the setbacks that local governments can apply at fifteen feet from the front property line and five from the other sides—with an exception allowing up to twenty-five feet of setbacks for buildings near wetlands, lakes, and streams.
• Maryland’s SB 36, if passed, would prevent local governments from regulating, for homes served by city water and sewer, “minimum square footage or exterior dimension requirements for a single–family home,” “lot coverage maximums for a single–family home and any accessory structures,” or setbacks for single family homes greater than ten feet on the front and rear property lines and five feet on the sides.
• Finally, Hawaii lawmakers are considering a bill, HB 1734, that would preclude local zoning rules that mandate lots larger than 1,200 square feet, dictate setbacks greater than ten feet from the front of the property, and would require projects to have “more than thirty per cent open space or permeable surface.” The change would walk back the more expansive zoning authority that Hawaii counties currently enjoy, which broadly empowers counties to regulate the “location, height, bulk, number of stories, and size of buildings and other structures,” the “percentage of a lot that may be occupied,” and “[m]inimum and maximum lot sizes.” Haw. Rev. Stat. § 46-4(6), (10–11).

Getting Smarter on Density

Denser cities can be more energy efficient and affordable for residents, so from that perspective encouraging denser development could have many benefits. But it can also have drawbacks. Although zoning can create sprawling, energy-inefficient neighborhoods, it can also be used to adapt to a changing climate in a huge range of ways. Since the adaptation measures cities might implement will look different across the country (depending, for example, on local climate conditions), retaining local flexibility is essential.

For example, where increased precipitation is a major climate-driven risk, cities might use their power to enforce how much space is kept open and permeable to mitigate flooding. Where extreme heat is a municipality’s main concern, setbacks can create additional space for tree planting that creates shade and evapotranspiration to cool cities. And density can be explicitly traded for green building practices of almost any kind through a range of point-based green area ratio systems that grant extra height, unit density, or aesthetic flexibility in exchange for green roofs, green stormwater infrastructure, tree planting, and similar development choices.

Both the variety of approaches available and the precision with which they can be applied if a city has that flexibility counsel against a blanket rule applied across the whole state at once. Local elected leaders know this well: in the last several weeks two small communities in Michigan passed resolutions urging the legislature not to preempt local zoning power. Linden, Michigan resolved that “preemption of local zoning authority circumvents the role of local officials and reduces the ability of local control to balance growth, infrastructure capacity, public safety services, environmental protections, fiscal responsibility; and long-term planning goals of their communities.” In the same spirit, nearby Fenton Township added that:

Local governance rewards participation and encourages problem-solving. It creates spaces for communities to wrestle with complex issues, adapt to changing conditions, and take ownership of the solutions they implement. Durable outcomes emerge when people have a voice, a stake, and a responsibility in shaping decisions that affect their communities and their families.

They’ve got a point. Local conditions vary considerably even within individual states. Letting local leaders make final decisions on zoning leaves room for zoning regulations that are responsive to unique conditions and for which local authorities can be held directly accountable through democratic processes. Statewide preemption allows for neither.

Moving Forward

I offer three suggestions for state legislatures considering bills like the examples discussed above. First, rather than rewriting particular zoning codes, states should get creative with alternative legislative approaches and more nuanced governance reforms. A few examples highlight the breadth of options available to states that do not rely on preempting local control. Funding programs designed to encourage developers to pursue large, affordable development even within local zoning constraints are a classic example. Other options could include legislation requiring cities to create neighborhood-scale opt-out mechanisms—like this one in Houston—to allow cities themselves to make changes to their zoning code and put the burden of obtaining consensus on opponents to reform, rather than on the city in the first instance. Or, especially for the benefit of smaller municipalities without the resources to engage in detailed mapping projects of their own, conducting statewide mapping efforts that identify areas where density is appropriate—and where retaining additional open space may deliver greater net benefits. And finally, where feasible, opening up conditional sales of air rights held by the state to promote more housing without changing the underlying authority of cities to zone.

Second, where preemption measures are adopted, states should add explicit, carefully-targeted carve-outs for adaptation measures. Any exceptions to blanket rules applicable across the whole state create the possibility for abuse, but leaving no room to adapt to local conditions precludes even appropriate uses of regulatory flexibility. For example, allowing larger setbacks in specific areas may be a great way to protect specific, important wetlands and waterways, and corridors with larger areas of permeable surfaces may protect larger areas from the worst flooding risk. That can’t happen if cities lack the authority to make situation-specific decisions appropriate to their unique local conditions.

Third, states should pair zoning reform proposals with measures to adopt or exceed the latest model energy codes. Doing so can make housing considerably more affordable without upsetting the balance of power between cities and states. A handful of states have already adopted modern energy efficiency codes, but adopting modern energy codes is far from universal. Updated energy codes will help achieve long-term affordability for residents and enhance—rather than risk hindering—climate resilience.

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As legislatures make moves to increase access to affordable housing they should be careful not to take such sweeping action that they interfere with local governments’ ability to adapt to a changing climate. Reining in state-level preemption, exploring deeper innovations in governance, designing reforms with adaptation-focused exceptions, and engaging in parallel work to advance modern energy codes can all help states tackle affordability without giving up local governance.