Map sources

A living inventory of the cartographic and geometry data sources behind the Uitwijken.nl map — the base tiles, administrative boundaries, and address/building geometry that make cascading geography possible before there is any user activity.

This page is concrete vendor- and API-level detail, the map counterpart to Event-sources (which inventories event pins). The principles for why open data matters live in Open-data. The dated record of how this inventory was built lives in Research-log.

Unlike events — where the salient question is commercial gating — almost every source here is open Dutch government data. The axis that matters is layer function: what each source contributes to the stack. Most of the foundation is served by PDOK (the national geodata platform, run by Kadaster) and data.amsterdam.nl (the municipal DSO-API), both free and no-auth.

Last reviewed: 2026-06-02

Recommended stack

A buurt-scale civic map can be built end-to-end on open data with no commercial dependency:

1. Base canvas — PDOK BRT Achtergrondkaart vector tiles (free, CC-BY). MapTiler/Mapbox only if a custom global style is ever worth the cost.
2. Boundaries — Amsterdam gebieden API for the city's own stadsdeel → wijk → buurt hierarchy (this is the indeling the platform should use); CBS Wijk- en Buurtkaart when national comparability or statistics are needed.
3. Addresses & buildings — PDOK BAG OGC API / vector tiles for the map layer; PDOK Locatieserver for the search box; Kadaster BAG Individuele Bevragingen for "what's at this point" lookups.
4. Street-level detail — PDOK BGT vector tiles when zoomed into a single buurt (pavements, greenery, water).
5. Civic overlays — events via Event-sources; meldingen, permits, plans via the municipal DSO-API and Open-data.

Rationale: prefer national basisregistraties (stable, authoritative, openly licensed) for the foundation; use Amsterdam's own services where the city's indeling or freshness beats the national mirror.

What the layers look like

Live previews pulled straight from the open services — same central-Amsterdam location across the base-map styles. These are hotlinked from PDOK (no captured screenshots); if they ever fail to load it's a transient service issue, not a broken inventory.

BRT-A base-map styles (standaard · grijs · pastel · water):

CBS buurt boundaries (WMS render over central Amsterdam):

BAG building footprints (WMS render, centrum):

Base map tiles — the canvas

Administrative boundaries — the cascading scales

Addresses & buildings

Street-level detail

Civic overlays

The layers that drape on the base map. These mostly live in other inventories — listed here so the full map stack is legible in one place.

Open questions

These weren't fully resolved in the 2026-06-02 scan and are worth a follow-up before locking the architecture:

• Platform API keys. Both PDOK-side BAG (Individuele Bevragingen) and data.amsterdam.nl are rolling toward mandatory keys with no firm deadline announced. Code should be ready to send a key. This is the biggest forward-looking risk for a third-party integrator.
• Exact BAG/BGT collection identifiers — verify against the live /collections JSON before hard-coding field names.
• Amsterdam gebieden license string — the dataset page shows "Licentie: -" while the data is openbare data; behaviorally CC-BY but not formally tagged. Confirm before relying on attribution terms.
• Municipal map-relevant datasets (parkeervakken, bomen/trees, and the broader permits/plans layer) — named in Open-data but never inventoried at endpoint level the way events were. A natural next dive.
• Vector-tile performance at buurt scale — BGT detail is heavy; test real render budgets before committing to it as more than a zoomed-in layer.

Implications for product

• The map foundation is a closed question. Base tiles + boundaries + addresses can ship entirely on PDOK + data.amsterdam.nl, free and openly licensed. No commercial cartography dependency is required for the proof-of-concept.
• Use Amsterdam's indeling, not CBS, for the platform's scales — but keep the cbsCode link so national statistics can still be joined.
• One geocoder, one base style, reused everywhere — invest in the PDOK Locatieserver search box and a single BRT-A style as shared infrastructure, the same way Event-sources argues for one JSON-LD extractor.
• Licensing is mixed — BGT/NWB are CC-0, BRT-A/CBS are CC-BY (attribution line needed), Amsterdam basiskaart has bespoke terms. Track per-layer attribution from the start.
• What's still open is the civic-overlay layer — permits, plans, budgets — not the cartography. That's where the next research dive should go.

Tags

#year/2026 #city/amsterdam #data/maps