Separation of Uses

Definition

Separation of uses is the zoning doctrine — validated by the courts in Village of Euclid v. Ambler Realty Co. (1926) — requiring "the complete segregation of residential land from commercial and/or industrial uses." In Wentling's practitioner account, it is the root doctrine of postwar suburban form: "Initially justified by the perceived need to protect residential neighborhoods from encroaching factories moving out of city cores, this doctrine was carried to absurd conclusions—which is why in most of our suburban communities it is impossible to buy a loaf of bread without getting into a car and driving for 15 min to get to a store" (Wentling 2017, p. 59). Its residential-design corollary is the "planned unit development" (PUD, later "master-planned community," MPC): housing types sorted into segregated pods by a "circles" recipe — "spread a piece of paper over a site survey. Start drawing circles. Label those circles with different housing types" (p. 59) — which "contrasts with the more integrated uses and architectural variety found in traditional towns and prewar suburban plans" (p. 60). The doctrine also outlawed the corner store ("With the introduction of zoning and the doctrine of separation of uses, corner stores were outlawed," p. 62) and produced the strip center as the postwar retail prototype.

The concept is thus the zoning-legal engine of the cluster's diagnoses: where Keil names "private authoritarian suburban ways of life" and Cochrane et al. the growth politics, separation of uses is the juridical instrument that made the car-dependent, single-use suburb the default — and the thing the New Urbanism's mixed-use, pedestrian-oriented programme (new-urbanism, missing-middle-housing) seeks to reverse.

Key Thinkers

• wentling-james — the practitioner's audit: Euclid as root doctrine, MPC circles as its design corollary, the 15-minute loaf of bread as its absurd conclusion (2017)

• Richard Babcock (not yet paged — see log) — The Zoning Game (1966, 1985): the early identification of poor municipal practice cited in the book's bibliography

• Jane Jacobs — the doctrine's planning-theory genealogist and chief critic (1961): the sorting principles traced from Howard's Garden City through the Decentrists to "today a land-use master plan for a big city is largely a matter of proposed placement… of many series of decontaminated sortings" (p. 26)

Related Concepts

• new-urbanism — the reform movement formed against the doctrine
• mixed-primary-uses — the first of Jacobs's four conditions: the positive programme the doctrine prohibits
• suburban-governance — the local "police power" regime that administers the separation
• urban-sprawl — the settlement pattern the doctrine produces
• missing-middle-housing — the mixed-type programme that reverses the residential side
• privatised-public-space — the strip-center/stop-and-shop retail form the doctrine produced
• automobile-vernacular — the mobility condition the doctrine presupposes and reinforces

Source Support

Sources in the wiki that discuss this concept:

• Designing a Place Called Home (Wentling 2017) — Euclid v. Ambler as validation (p. 59); the "impossible to buy a loaf of bread" formulation (p. 59); the MPC circles recipe (p. 59); the corner store's outlawing and the strip-center retail prototype (pp. 62–63); the mixed-use "living over the store" programme and its "free space" economics (p. 218)
• The Death and Life of Great American Cities (Jacobs 1961) — the doctrine's intellectual ancestry: Howard "conceived that the way to deal with the city's functions was to sort and sift out of the whole certain simple uses, and to arrange each of these in relative self-containment" (p. 18); the Decentrists' verities ("The street is bad as an environment for humans… Commerce should be segregated from residences and greens. A neighborhood's demand for goods should be calculated 'scientifically,' and this much and no more commercial space allocated," p. 20); the Radiant City and City Beautiful mergers into "a sort of Radiant Garden City Beautiful" (p. 25); the monopoly planning that protects one-age districts' commerce ("Thus it is that routinized monopolistic packages of substitute city are palmed off as 'planned shopping,'" p. 192); and the counter-doctrine — zoning for diversity, and the zoning reform whose "most serious fault… lies in the fact that they permit an entire area to be devoted to a single use" (Raskin, quoted p. 229) with Jacobs's own scale-of-frontage proposal (pp. 234–235). See mixed-primary-uses, new-urbanism, small-blocks.
• Dark Age Ahead (Jacobs 2004) — the doctrine's founding assumptions named as zoning's "three big ideas": "High ground coverages are bad. High densities (numbers of people or numbers of households per acre) are bad. The mingling of commercial or other work uses with residences is bad" — "All three assumptions are rejections of cities and city life, devised by utopians and reformers… The tools are unsuitable except for creating sprawl, even when they are subject to appeals and amended into incoherence" (pp. 153–154). The replacement proposal: "prohibitions of destructive performances" — the performance code regulating decibels, pollution, truck traffic, destruction of loved buildings, blighting signs, and street scale instead of uses, because "feared changes are not actually about land uses, densities, and ground coverage but rather about dreaded side effects" (p. 154). See performance-codes, mixed-primary-uses, densification.

This page requires fuller treatment — created at the Wentling ingest; the Jacobs (1961) ingest has supplied the planning-theory ancestry; awaits the Euclid legal-historical literature directly.

Open Questions

• Is separation of uses a doctrine (a legal idea with a history), a symptom (of property-value protection, i.e. class exclusion), or a technology (the administrative machinery of suburban growth)? The sources support all three framings.
• How does the concept's juridical register connect to suburban-governance's tri-modal governance — is zoning the state modalities' local face?
• Wentling notes zoning's defenders used it against factories, yet the doctrine's "absurd conclusions" harmed the very residential quality it claimed to protect (no walkable retail, no corner stores). When does protective zoning become extractive?