NL AHN Hoogtedata Lookup per Adres

Looks up official Dutch elevation data — ground level (DTM) and surface height (DSM, including buildings and vegetation) — from the national AHN height map for any address, postcode, or coordinate. Also returns the derived above-ground height (building/vegetation height), computed from the difference between surface and ground level.

When should an AI agent use this?

• "What is the ground-level elevation at this address, relative to NAP?"
• "How tall is the building at this address, based on official elevation data?"
• "Check flood-risk-relevant ground elevation for a batch of addresses."
• "Get the surface height (including rooftops) at these coordinates for a solar-panel orientation study."
• "Compare ground elevation across a list of addresses for a drainage/water-management analysis."
• "Estimate building or tree-canopy height above ground for these locations."

What this Actor does

• Geocodes any Dutch address, postcode, place name, or "lat,lon" coordinate via the official PDOK Locatieserver
• Queries the official AHN (Actueel Hoogtebestand Nederland) WCS, PDOK/RWS, for the DTM (ground level) and DSM (surface height) at that location — 0.5m resolution, CC0
• Returns ground level as the median of the surrounding data rather than the single exact pixel — because AHN's ground layer has no data directly under a building's roof, sampling only the exact point often returns nothing for addresses (which are usually on top of a building)
• Returns surface height as the exact pixel at the point (e.g. the rooftop height)
• Computes the derived above-ground height (surface minus ground) — a rough proxy for building or vegetation height
• Processes up to 50 locations per run, with configurable concurrency

Input

Field	Type	Description	Example
locaties	array of strings	Address, postcode, place name, or "lat,lon" per location (1-50)	["Bathseweg 27, Rilland"]
concurrency	integer	How many locations to process in parallel	3

Output

{
  "invoer": "Bathseweg 27, Rilland",
  "gevonden": true,
  "fout": null,
  "foutcode": null,
  "weergavenaam": "Bathseweg 27, 4411BA Rilland",
  "postcode": "4411BA",
  "gemeente": "Reimerswaal",
  "provincie": "Zeeland",
  "lat": 51.41533763,
  "lon": 4.18586885,
  "geocodingScore": 19.1,
  "geocodingBetrouwbaarheid": "hoog",
  "maaiveldhoogteMeter": 1.81,
  "oppervlaktehoogteMeter": 8.23,
  "opstandhoogteMeter": 6.42,
  "dekkingBeschikbaar": true,
  "eenheid": "m t.o.v. NAP",
  "bron": "AHN WCS (service.pdok.nl/rws/ahn/wcs/v1_0) + PDOK Locatieserver (geocoding)"
}

fout is a human-readable error message (null on success). foutcode is a machine-readable classification for agents/automation, one of:

Code	Retryable?	Meaning
null	—	No error.
GEEN_GEOCODING_MATCH	No	PDOK Locatieserver found no match for this input — retrying the same input won't help.
UPSTREAM_ERROR	Yes	Temporary HTTP/connectivity failure at PDOK Locatieserver or the AHN WCS (after built-in retries) — a later run may succeed.
ONBEKENDE_FOUT	No	Unexpected error that doesn't fit the categories above.

Use cases

• Add ground-elevation context to a flood-risk or drainage analysis for a portfolio of addresses
• Estimate building height for a solar-panel feasibility or shadow-impact study
• Enrich a real-estate or land-development dossier with official elevation data
• Batch-check elevation for a set of construction sites before a site-preparation assessment

Pricing

This Actor uses Apify's Pay-Per-Event (PPE) pricing model.

• Actor Start: $0.00005 (Apify default)
• locatie-resultaat: $0.006 per location checked

Legal

Uses only official, open, CC0-licensed government data: the AHN WCS (PDOK/RWS) for elevation, and the PDOK Locatieserver for geocoding. No personal data is processed. Elevation values are official survey-grade AHN data (laser altimetry, ≥10 measurements/m²), but the derived above-ground height is a simple surface-minus-ground calculation, not a validated building-height measurement — treat it as an indicative figure.

FAQ

Q: Why is the ground-level value a median of the surrounding area instead of the exact point? A: AHN's ground layer (DTM) has no laser-ground-return data directly under a roof — since most addresses point at a building, sampling only the exact pixel often returns nothing. The median of the surrounding window gives a meaningful "ground level near this address" value instead.

Q: What does "above-ground height" measure? A: The surface height (DSM, exact point — typically the rooftop or treetop) minus the surrounding ground level (DTM median) — a rough proxy for building or vegetation height, not an official measurement.

Q: What if a location has no AHN data (e.g. open water)? A: dekkingBeschikbaar is false and the relevant height field(s) are null — AHN's DTM excludes water, and DSM excludes most water surfaces too.

Q: Which AHN version is used? A: AHN4 (2020-2022 acquisition), the current version served via PDOK's national WCS at 0.5m resolution.

Related Actors

• NL Bodemrisico Check — same geocoding pattern, checks the same address against known soil contamination instead of elevation.
• NL Natura2000 Afstandscheck — same geocoding pattern, checks distance to protected nature areas.
• Vastgoed XXL — combines multiple official Dutch geo-data sources into one property dossier; a natural companion enrichment.

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Zoekwoorden: AHN hoogtekaart, maaiveldhoogte, hoogtemeting adres, NAP-hoogte, DTM DSM Nederland, hoogtedata opvragen, gebouwhoogte schatten.

Keywords

ahn, elevation, hoogtedata, netherlands, pdok, dtm, dsm, ground-level, building-height, geocoding

Changelog

0.1.0

• Initial release.