Single-Use Zoning: Bad Human Habitat’s DNA

With the human scale offering so many advantages over auto-dependent development, it begs the question why America remains locked into producing bad human habitat. To better understand the why, it’s helpful to first know something about bad human habitat’s DNA. That DNA is called single-use zoning.¹

Zoning Fundamentals

Zoning fundamentals are easy to grasp. Your local government maintains a map of your municipality that’s divided into zones. Each zone encompasses one or more pieces of property owned by various landowners. Your municipality assigns each zone on the map a zoning classification that falls under one of a handful of parent classifications. Below is a single-use zoning map from New Britain Borough, PA, not too far from where I grew up.

In the U.S., parent classifications are typically residential, commercial, industrial, open space, and agricultural. You’ll find descriptions for these zone classifications in your local government’s zoning regulations.

For each zone classification in this document, you’ll find two important subsections. The first subsection lists permitted uses for a zone classification. For example, the Baltimore County zoning ordinance (where I worked as a legislative planner) has a commercial zone called Local Business, whose list of uses is extensive, including everything from convalescent homes to restaurants.   

The second subsection contains information collectively referred to as bulk requirements, which regulates, among other things, maximum building dimensions and how far back a building must be from the property line. In Baltimore County’s Residential Office zone, for example, you find regulations governing characteristics such as floor area ratio, building height, and side yard setback.

That’s it in a nutshell. There’s more to zoning, but this is all we need to understand for our purposes here.

Zoning is Not the Problem. Single-Use Zoning is the Problem

Zoning itself isn’t the problem. Nobody wants to buy a home and then watch a factory get built next to it. This was the scenario the Germans wanted to avoid when they invented citywide zoning in the 1870s.² And long before that, going back to antiquity, people have been making laws shaping cities. America’s problem is that it implements a variant of zoning known as single-use zoning.

With single-use zoning, a municipality only allows residential uses in residential zones and commercial uses in commercial zones. Municipalities create separate zones for different housing, such as single-family homes and apartments.³ In Pennsylvania, I grew up in a zone classified as “Residential Suburban” which allowed developers to build single-family homes on quarter-acre lots and a community swimming pool. The municipal government prohibited every other use.

No Single-Use Zoning in Germany

Single-use zoning does not exist in Germany. All residential zones permit some combination of commercial and residential uses.⁴ You want to operate a bakery in a residential zone? No problem. A restaurant? No problem in most residential zones.

Germany’s residential zones are better understood to be “living zones” and within these zones, you can operate a full range of businesses considered integral to daily life. Even a relatively restrictive zone called “Exclusively Residential” permits small shops, hotels, and civic buildings. And importantly, single-family zoning doesn’t even exist in Germany. All residential zones allow townhouses, apartments, condominiums, and single-family homes.⁵

An American Tragedy – Single-Use Zoning

America is a world apart from Germany concerning zoning. Seventy-five percent of residential property across the country is zoned for single-family housing.⁶  In the remaining 25%, townhouses go in a townhouse zone, apartments go in an apartment zone, and so on. Municipalities routinely create residential zones with different minimum lot sizes to further segregate people by income.

The net effect of single-use zoning is to put physical distance between you and everything you’d need to access outside the home over a week. Walking is impractical, so you drive. And when you get to your destination, you park in a lot. The minimum parking requirements found in your municipality’s zoning regulations dictated the size of that lot.

Typically, parking requirements are based upon theoretical worst-case scenarios, such as everyone driving to the shopping mall on Black Friday. This is why America has 800 million surface parking spaces that collectively consume a land mass larger than Puerto Rico.⁷ In many urbanized areas, parking consumes more than a third of the land area.⁸

Single-use zoning produces a built environment that requires an automobile for everything except a walk around the block. And even that’s a questionable proposition in many places.

Communities have much to gain by rejecting single-use zoning and embracing human-scale development. The rule of perpetual urban sprawl need not be every municipality’s destiny. There is a path forward that produces a very different outcome, but it requires more from local politicians, developers, urban planners, and citizens alike. Please consider working within your own community to replicate the success experienced elsewhere. Future generations will thank you for your efforts.

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1. You also may hear single-use zoning referred to as Euclidean zoning. ↩︎
2. Sonia Hirt, “To Zone or Not to Zone? Comparing European and American Land-use Regulation,” PDN Online, 2010, https://www.researchgate.net/publication/262223629_To_Zone_or_Not_to_Zone_Comparing_European_and_American_Land-use_Regulation. ↩︎
3. The name “single-use” is somewhat misleading. Within a single-use zone, you can have multiple uses, but they all fall under a single top-level category, such as commercial or residential. For example, in a single-use commercial zone, you might find multiple uses lists such as a restaurant, automotive repair, retail shop, etc. ↩︎
4. Sonia Hirt, “To Zone or Not to Zone?,” (Note 2). ↩︎
5. Ibid. ↩︎
6. Ibid. ↩︎
7. Peter Dizikes, “Lots of Trouble,” MIT News, March 2012,  https://news.mit.edu/2012/parking-lot-redesign-0313. ↩︎
8. Ibid. ↩︎