🏙️ How Planners Quantify a Liveable City

About this simulation

Urban planners judge whether a district can support a healthy population using a handful of ratios: dwellings per hectare, square metres of green space per resident, and how many people live within an easy walk of frequent public transport. This model builds a simplified neighbourhood block on a parcel grid and recomputes all three ratios live as you change the underlying policy levers.

How it works

• Housing density — sets the average building height (floors) across buildable parcels. Taller buildings mean more dwellings and more residents per hectare.
• Green space share — converts a percentage of parcels into parks with trees instead of buildings, directly trading off against buildable floor area.
• Transit frequency — vehicles per hour serving the central hub. More frequent service is realistically judged to extend the practical "walkable" catchment, since shorter waits make longer walks worthwhile — so the 15-minute catchment ring grows with frequency.
• Mixed-use ground floors — toggles active ground-floor retail, a hallmark of the "15-minute city" concept where daily needs are reachable on foot.

Reading the stats

• Green space / person is compared against the commonly cited WHO benchmark of roughly 9 m² of accessible green space per resident.
• Transit load compares estimated peak-hour ridership demand against the modelled line capacity — over 100% means crowding.
• Liveability score blends density, green provision, and transit performance into one indicative number — there is no single "correct" answer, only trade-offs.

Did you know?

Doubling a district's density does not just double transit demand — it changes which service frequency is economically viable, which is why density and transit capacity planning are treated as a single, linked problem rather than two separate ones.