At last week’s Low & Moderate Density zoning review meeting, the group discussed what aspects of the residential zoning code don’t work well. Many mapped to real problems with the zoning code, like the fact that numerous neighborhoods are illegal to build under the current zoning because most of the current buildings are closer to the lot lines than the rules allow. As I’ve argued in the context of parking, we should write rules that, at the very least, allow the type of buildings that exist today.

But other issues crossed a line into busybody-ism, regulating behavior rather than buildings. For example, we discussed whether to limit the number of families allowed in a building. Current zoning in low-density areas also specifies the buildings as being single-family. Should we continue that?

I believe that it’s not the business of zoning to decide whether people are related to each other or not. Families 50 years ago were much larger, and a single-family home may have housed 6-8 people. Today, that’s more likely 2-4, meaning unless we allow two families per building, we’re forcing a lower population than previously lived in the neighborhood.

Late in the meeting, a few members of the Office of Planning said something that frightened me. When discussing R-5-B zones, which allow a wide range of building types, the presentation (slide 30 here) listed as a problem that the zone is “open-ended” and has “no predictability”. One of the Planning staff opined that “some regulation is better is no regulation.”

I beg to differ. While planning is a valuable tool, we must resist the urge to plan everything. Not regulating something should be our default position. (Arguing this in the meeting, I even found myself sounding like anti-planning zealots like Randal O’Toole!) Where I part ways with the libertarians, however, is that regulations are reasonable when they are solving a specific and valid problem. Simply putting in zoning to ensure “predictability,” however, is not solving a specific or valid problem.

What’s the difference between a good regulation and a bad one? Let’s look at the standards courts use to declare laws constitutional or unconstitutional. In the “strict scrutiny” form of review, a law must satisfy three requirements:

  • It must fulfill a compelling governmental interest
  • It must be narrowly tailored to accomplish the goal, meaning it should avoid affecting other behavior outside the compelling interest
  • It must use the least restrictive means possible

Zoning laws aren’t subject to strict scrutiny (and shouldn’t be): controlling buildings isn’t as “compelling” as required for strict scrutiny, and the zoning laws shouldn’t have to take the absolute least restrictive means possible, as strict scrutiny would require. Courts generally use other types of scrutiny for these laws. However, these are useful principles to keep in mind when designing a zoning law. Each rule should address a specific problem (the compelling interest), attempt to restrict only the behaviors involved in the problem (be narrowly tailored), and try to limit the amount of restrictiveness to the least necessary.

A good example is underground development. At the meeting, Anne Lewis, architect and former member of the HPRB, brought up a problem of people building structures underneath their backyards, like a basement rec room that is larger than the rest of the building. The current zoning rules allow this. Should we change them to prohibit it?

Lewis mentioned several problems that can arise from such structures. They prevent any trees from growing, could create drainage issues, and might affect surrounding property owners’ foundations. But under the scrutiny principles, banning such structures outright doesn’t fly. Having trees, ensuring drainage, and protecting neighbors’ foundations are legitimate interests, but we could instead narrowly tailor the rules to mandate that such development must leave enough soil for a certain size of tree, must be designed with adequate drainage, and must contain support structures to protect surrounding foundations. We can create rules to solve the specific problems without banning the practice entirely. Simply saying “well, they should be able to live without the rec room,” as another person did in the meeting, isn’t a good enough reason.

Alley dwellings represent another example. Right now, they are only permitted on alleys of over 30 feet. The only rational reason I have heard for banning them is that fire trucks can’t reach them. But fire trucks are only about 12 feet wide. We should allow alley units as long as they are reachable by fire trucks, narrowly tailoring the restriction to only prohibit units that violate the actual reason for the rule.

Again, I’m not suggesting courts should strike down most of our zoning laws under strict scrutiny principles. In fact, I’m a supporter of leaving most decisions to the political process instead of to judges, except in extremely important areas like civil rights. But whether we’re talking about parking minimums, accessory dwellings, underground structures, height limits, blocking windows in ground-floor retail, or historic preservation, it’s helpful to keep these principles in mind.

Zoning rules are absolutely appropriate to solve these problems. But we must take care to regulate only in order to address the specific issues, not simply for the sake of doing it or to ban anything that’s unusual. If we over-regulate, then we’re giving credibility everything the absolutists say about planning and planners.

David Alpert is Founder and President of Greater Greater Washington and Executive Director of DC Sustainable Transportation (DCST). He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He lives with his wife and two children in Dupont Circle. Unless otherwise noted, opinions in his GGWash posts are his and not the official views of GGWash or DCST.