report · PL-2026-07 · October 2026

The 15-minute gap

M. de Wit, S. Yilmaz, P. Okoro · 24 pages · open data and code

We measured walking times from all 462,000 homes in the city to the nearest GP, primary school and grocery store. Three in four homes reach all three within 15 minutes. The quarter that don't are concentrated in five post-war districts — and most of the gap could be closed with eleven new small premises.

462khomes analysed
74.6%reach all three in 15 min
11sites would close 60% of the gap
Walking-time rings around a neighbourhood centre
Fig. 1 — 5, 10 and 15-minute walking areas from a typical neighbourhood centre.
80%70%60%201620212026 74.6% post-war districts
Fig. 2 — Share of homes within 15 minutes of all three services, city (blue) vs. post-war districts (orange).

Method

Walking times were computed on the full pedestrian network, including footpaths through parks and courtyards, at 4.5 km/h. Services come from the municipal register, cleaned against business licences and checked on site in a 5% sample.

What it means

The gap is not about density — some of the densest blocks are well served. It is about missing ground floors: post-war estates were built with homes on every level and nothing else. Converting small ground-floor units is faster and cheaper than any new building.