Sustainable City Land-Use Simulator

City Design

Building density 140 du/ha

Green space share 18%

Transit coverage 35%

Sustainability Index

Composite score (0–100)

—

Building energy

—

Transport CO₂

—

Heat-island ΔT

—

Population / block

—

How it works

Three planning levers set the shape of a 10×10 city grid, and three empirically-grounded relationships from urban-sustainability research turn them into outcomes:

Building energy/capita:
  E(D) = E0 · (D0/D)^0.3
  (taller, denser blocks share walls & HVAC systems —
   per-capita heating/cooling load falls with density)

Transport CO2/capita:
  C(D,T) = C0 · (1 − 0.55·T) · (D0/D)^0.3
  (Ewing & Cervero "compact city" elasticity: both
   transit coverage T and density D cut vehicle-miles
   travelled and thus per-capita transport emissions)

Heat-island intensity:
  ΔT = ΔTmax · (1 − G/Gmax) · (D/Dmax)^0.5
  (impervious, dense fabric raises canopy temperature;
   vegetation cover G is the strongest known mitigator)

Density slider — dwelling units per hectare; taller instanced towers rise on the grid as it increases.
Green space slider — fraction of blocks converted to parks; lowers heat-island ΔT but reduces buildable area (raising effective density elsewhere), a genuine trade-off.
Transit coverage slider — fraction of blocks within walking distance of a transit line, drawn as glowing rails; cuts transport CO₂ directly.
The Sustainability Index normalises each of the three outcomes to 0–100 against realistic best/worst bounds and averages them — it rewards the combination that lowers all three together, not any single lever pushed to its extreme.

These are planning-literature order-of-magnitude relationships, not a building-by-building energy model — the point is to show how the three levers interact, which is exactly the trade-off real urban-sustainability plans have to navigate.

Buildings (height = density) Green space Transit lines

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.