Resource Paspoort
A materials passport for Dutch buildings — look up any building on official government geodata.

React (Vite)SupabaseMapLibre GLBAG WFS / PDOK3DBAG
Die Herausforderung
The built environment is going circular, and buildings increasingly need a 'materials passport' — but the underlying building data is spread across government services and isn't trivial to query or map.
Was ich gebaut habe
A materials-passport web app that looks up Dutch buildings, renders their footprints on an interactive map, and enriches them with heights — pulling from the free official BAG and 3DBAG services.
Stack & Warum
React (Vite)
A fast, lightweight SPA for the lookup + map experience — quick to iterate.
Supabase
Postgres + auth for storing passport data without a custom backend.
MapLibre GL
Open-source vector maps — no per-tile bill and full control over styling, ideal for a data-heavy building map.
BAG WFS (PDOK) + 3DBAG (TU Delft)
Free, authoritative Dutch data: BAG for building footprints and dwellings, 3DBAG for height and roof metrics — no paid GIS provider needed.
Wie es funktioniert
- Building footprints come from the BAG WFS and are rendered on a MapLibre map; heights and roof metrics are layered in from the 3DBAG API.
- Trickiest bit: the BAG WFS rejected the obvious cql_filter parameter — solved by building a proper FES filter (fes:PropertyIsEqualTo on the building id) in src/lib/bag.ts to query buildings correctly.
- 3DBAG sends no CORS headers, so its data is fetched through a small proxy rather than directly from the browser.
Ergebnis
- ✓A working materials-passport map on free, authoritative government data.
- ✓No paid GIS or geocoding provider in the stack.
Meine Rolle
Engineer — app, geodata integration and map.
Bereit, KI wirklich arbeiten zu lassen?