Parks, Plazas and the Public Realm#
SLOP2418 — Urban Design Studio
Week 9 · Tobias Wren · 3 May 2027
direct readout · derived measure · worked hypothetical
Assessment 2 is due today#
Public Realm & Infrastructure Plan — 25% of the studio. Pinned up before the jury sits: Tobias Wren (chair), Sunniva Marek. The Course Convenor is not in the room this week.
Sunniva Marek is a principal at Kesselring & Marek and is not teaching staff. They were not at your desk crit. They arrive with your screenshots, your memo, and the four-minute wall clock the brief names.
Assessment 2, walked#
| Item | Requirement |
|---|---|
| Weight | 25% of the studio |
| Due | Monday of Week 9, 12:00; defended at the jury at 14:00 |
| Criteria | livability 45 · fiscal 30 · mobility 25 |
| Deliverable A | 8–12 in-simulation screenshots, captioned, including at least one attractiveness overlay, one land value overlay, one water or sewage info-view, and one street-level view at night |
| Deliverable B | defence memo, 1,200 words maximum, structured against the three criteria in that order |
| Deliverable C | one costed budget line for every public space proposed, monthly, funded from the closure you set in Week 8 |
| Format | four minutes at the wall: ninety seconds for one claim, the rest for questions; changeover inside the four minutes |
The three criteria are not three sections of a plan. They are three claims about the same plan, and a memo that argues each one separately is arguing with itself.
Two definitions of a park#
- What a park is for: optional presence. People being somewhere they did not have to be, for as long as they like, with nothing to buy.
- What the readout measures: an attractiveness contribution within a service radius, a visitor count, and a monthly upkeep figure.
- The second is a proxy for the first and it is a poor one. It cannot tell a plaza with 400 people crossing it from a plaza with 400 people sitting in it.
- So the readout is the screening tool and the street-level view at night is the evidence. The brief asks for both, in that order.
Jacobs’s three conditions#
A street works, Jacobs argues (1961), when three things hold at once:
- There is a clear demarcation between public and private space, and they do not ooze into one another.
- There are eyes upon the street — buildings oriented towards it, with the doors and windows facing the thing they are supposed to watch.
- There are users on it fairly continuously, which adds eyes and gives the people in the buildings a reason to look.
All three are decisions about the frontage. None of them is a decision about the park.
Jacobs on eyes upon the street#
There must be eyes upon the street, eyes belonging to those we might call the natural proprietors of the street.
— Jane Jacobs, The Death and Life of Great American Cities, 1961
The same 120 metres, twice#
At 13:00 both frontages move people. At 22:00 only one still has eyes on the street.
What Whyte actually counted#
Whyte’s group observed small plazas directly, over months, and ranked what predicted use (1980):
| Factor | Whyte’s finding | Where it appears in the build |
|---|---|---|
| Sittable space | the strongest single predictor; roughly one linear foot of seating per 30 sq ft of plaza | plaza props and their upkeep line |
| Relation to the street | the best-used plazas were level with the footpath and open along it | the footpath graph’s connections to the plaza edge |
| Food | a food source close by raised use substantially | ground-floor commercial demand at the edge |
What Whyte actually counted, continued#
| Factor | Whyte’s finding | Where it appears in the build |
|---|---|---|
| Sun | plazas in shade after mid-afternoon emptied | building heights on the northern edge, under the day/night cycle |
| Water and trees | used, touched, sat under; not decorative | park props, and the upkeep they add |
| Triangulation | an object or event that gives strangers a reason to speak | the one factor with no mechanic; argue it in the memo |
Whyte on what attracts people#
What attracts people most, it would appear, is other people.
— William H. Whyte, The Social Life of Small Urban Spaces, 1980
The plaza that does not work#
The overlay can report a contribution while the space itself fails six simple tests.
The third place#
Oldenburg (1989) lists eight characteristics. Four of them the studio can observe:
| Characteristic | In the build |
|---|---|
| Neutral ground | observable — no entry cost, no zoning that filters who arrives |
| Accessibility | observable — footpath graph, 300 m catchment, transit stop distance |
| The regulars | observable, weakly — a repeated visitor count across the day/night cycle |
| Low profile | observable — nothing about the plaza’s cost or props signals occasion |
The other four the build cannot show and the memo must argue instead: a leveller, conversation as the main activity, playful mood, a home away from home.
Where a third place works, ground-floor commercial demand appears against its edge without being zoned for. That is the closest thing to a measurement the studio has, and it is a good one.
The 19:00 test#
Gehl (1971) separates three kinds of activity in public space:
- Necessary — the walk to the bus, the walk to work. Happens regardless of the quality of the space.
- Optional — standing, sitting, looking, walking for its own sake. Happens only when the space is good enough.
- Social — arises out of the other two being present at once.
So the 08:00 pedestrian count tells you nothing: it would be the same across a car park. The studio’s protocol is the count at 19:00 in fine weather, read off the day/night and weather cycles, because that count is optional presence and nothing else.
Alexander, with the numbers#
- Pattern 61, Small Public Squares: a square much wider than about 45 to 60 feet — roughly 14 to 18 metres — stops working as a room. You can no longer read a face across it, and the enclosure stops doing anything.
- Pattern 106, Positive Outdoor Space: outdoor space has to be shaped and enclosed on most of its perimeter. Space that is what is left over after the buildings were placed will read as left over.
- Halstead Reach civic plaza is 60 m across, enclosed on one side, and was what was left over after the arterial alignment in Week 5.
- Three 18 m squares at its corners would sit inside Alexander’s figure and would cost less to maintain than the one 60 m square does.
One plaza, or eleven squares#
| Measure | One civic plaza | Eleven pocket squares |
|---|---|---|
| Footprint | 3,600 m², in one place | 11 × 320 m², along the Kerrow corridor |
| Build cost | ₡96,000 | ₡72,600 |
| Monthly upkeep | ₡6,800 | ₡3,410 |
| Population within 300 m | 1,900 | 7,400 |
| Attractiveness contribution | high, and local | moderate, and everywhere |
| Alexander 61 | fails at 60 m | passes at 18 m |
| Whyte on other people | forty people in one place | four people in eleven places |
| Pins up | very well | badly |
Livability against fiscal performance, at ₡310 a month#
- The distributed option is cheaper by ₡3,390 a month, reaches four times the population, and sits inside Alexander’s dimension.
- It is also eleven weak spaces instead of one strong one, and Whyte’s finding cuts against it.
- Neither option is free of the other metric. The eleven squares only reach 7,400 people if the corridor’s footpath connections are finished, and that is mobility performance spend recorded against a livability benefit.
The public realm is the cheapest livability on the corridor’s budget. Cheap is not the same as easy.
Five things the jury will ask#
- What does this space do at 19:00 that it does not do at 08:00, and where is the screenshot?
- How many linear metres of sitting space, against how many square metres of plaza?
- Which budget line pays the upkeep, and what did you cut in Week 8 to afford it?
- Which of your three criteria did you make worse, and by how much?
- Your infrastructure plan and your public realm plan are on the same brief. What do they have to do with each other?
This week#
- Monday is the jury. Bring the completed evidence and Week 8 closure; all preparation happens before the noon upload.
- Artefact due today at 12:00; jury at 14:00. Screenshots printed, memo on the wall, not on a screen.
- Walk your own plaza at 19:00 in fine weather before you photograph it. If nobody is in it, that is the finding and it belongs in the memo.
- Week 10 takes the same corridor under hazard and pollution load, so keep the save exactly as submitted.