Where Euclidean zoning came from, what it was built to prevent, and what separating uses costs a district in commute distance and land value.
8 March 2027
The argument#
Use separation was invented to solve a real problem — industrial nuisance landing on housing — and it solves that problem completely, at the price of making every trip in the district longer. The studio commits the separated scheme this week, as a cohort, so that everyone carries the same cost and can be held to it; the work is not choosing which cost to carry but being able to name the one you were handed, in figures, against the alternative you built in a sandbox and did not keep.
What you will learn#
- Trace use-based zoning from a public-health response to a legal instrument to a default habit, naming the four sources that mark the turns.
- Distinguish what separation actually prevents from what it is assumed to prevent, using the pollution overlays as the test.
- Produce two zoning schemes for the same block layout and compare them on commute distance and on ground, air and noise pollution exposure.
- State the zoning decision as an explicit trade between livability and mobility performance, with figures from both overlays.
Theory into practice#
- Ebenezer Howard, To-morrow: A Peaceful Path to Real Reform (1898), reissued as Garden Cities of To-morrow (1902) — the garden city’s concentric arrangement, with industry on the outer ring and housing held clear of it.
- Village of Euclid v. Ambler Realty Co., 272 U.S. 365 (1926) — the United States Supreme Court upheld comprehensive use zoning as a valid exercise of the police power; Justice Sutherland’s opinion contains the line that “a nuisance may be merely a right thing in the wrong place, like a pig in the parlor instead of the barnyard.”
- Clarence Perry, “The Neighborhood Unit”, in the Regional Survey of New York and Its Environs, Vol. VII (1929) — a residential cell sized to one elementary school’s catchment, about a quarter-mile radius, with arterials at the edges rather than through it and shops at the corners.
- Jane Jacobs, The Death and Life of Great American Cities (1961) — the first condition for diversity: a district must serve more than one primary function, so that people using it on different schedules are present at different hours.
- Andrés Duany, Elizabeth Plater-Zyberk and Jeff Speck, Suburban Nation (2000) — the argument for regulating built form rather than use, and the form-based codes that followed.
The deck walks through where each of these lands, slide by slide, against Halstead Reach’s own zoning choice.
Simulation mapping#
| Theory move | Cities: Skylines II mechanic | What students should watch happen |
|---|---|---|
| Euclidean use districts | The zoning palette — residential by density, mixed housing, row housing, low and high density commercial, industry, office — painted onto road frontage | The palette is itself a use-based code; there is no cell you can paint that does not name a use |
| Howard’s nuisance ring | Ground, air, water and noise pollution overlays, and industry’s ground pollution footprint | Industry’s pollution has a radius, and the radius is smaller than students expect and does not respect the zoning boundary |
| Prevailing wind and river flow | The wind arrows inside the air pollution view, WNW on this map; the Kerrow flowing north-west to south-east | Air pollution from Ombersley Flats leaves the map; the same industry sited upwind of Halstead Reach does not |
| Perry’s quarter-mile cell | Service coverage areas and their falloff with distance; the district painting tool for scoping policy and tax | One well-placed elementary school covers most of a Perry-sized cell, and covers very little of a dispersed one |
| Jacobs on mixed primary uses | Commercial demand, and the distance a citizen will path to reach a shop before the commercial building fails | Separated commercial that is too far away shows up as an abandoned building, not as a long trip |
| Separation as trip generation | The traffic volume overlay on the collector serving the residential quarter at 08:00 | Every trip a resident makes to work or to a shop crosses the same one or two links, because the code left them nowhere else to go |
Evidence standard. Named interface fields are direct readouts. Calculations shown from those fields are derived measures. Every fixed scenario value on this page is a worked hypothetical, not a captured run. See resources and evidence for access arrangements and worksheets.
The decision this week#
Livability against mobility performance, forced by where Halstead Reach’s industry goes: downwind and downstream on Ombersley Flats, clean but a long, bridged commute, against the eastern edge of the Reach, close but exposed to its own pollution footprint. The deck works both schemes’ figures side by side. Both get built this week; only the separated one is committed, and it cannot be defended at the jury without the sandbox figures that say what it cost.
Into the studio#
- Students arrive with the Week 2 block layout built and a block dimension committed to in metres; the session zones into it and cannot start without it.
- The session runs both schemes side by side — the assessed save for one, a sandbox save for the other — and reads ground pollution, air pollution and traffic volume on each at 08:00.
- The session assumes students can turn on the wind arrows inside the air pollution view and know the map’s prevailing direction from Week 1; if they cannot, the pollution comparison is meaningless and the first fifteen minutes go on recovering it.
- Students leave having committed one scheme to the assessed save, and having read the Assessment 1 brief, which is issued in the session.
Assessment connection#
Feeds Assessment 1, the Neighbourhood Unit Plan (Week 4, 25%) directly and immediately — the brief is issued in this week’s session, the unit is Perry’s, and the livability criterion at 40 marks is read largely off the pollution and service-coverage consequences of the zoning scheme committed to this week. The mobility criterion at 30 marks is read off the commute distances the scheme generates. Also builds toward Assessment 2, the Public Realm and Infrastructure Plan (Week 9, 25%), where the land-value consequences of the zoning pattern become the material of the argument.
Teaching team
- Marisol Quaye — convenor