What does NAP mean?
NAP, the Normaal Amsterdams Peil, is the zero the Netherlands measures all heights from. It's roughly the average sea level of the North Sea. So a house 2 metres above NAP is about 2 metres higher than the sea. A house 4 metres below NAP is lower than the sea and stays dry thanks to dykes and pumping stations. About a quarter of the Netherlands lies below NAP.
Where do the heights come from?
From the Actueel Hoogtebestand Nederland (AHN). Aircraft measure the whole country with lasers, with about ten measurements per square metre on average. For the ground we use the terrain model, for your roof the surface model. You can read more about the AHN in our article on the elevation map of the Netherlands.
Frequently asked questions
Is the height of my roof right?
Roughly. We measure the roof at the point of your address, and the top of a sloping roof may be just somewhere else. If your house is brand new or has been rebuilt, the measurement may be older than the house.
Why is the height different from what I see in the AHN viewer?
We take the height of the ground around your address, because nothing is measured under the house itself. On a slope or next to a dyke that can differ by a few decimetres from the point you click on.
Does this work in Belgium or Germany too?
No, these heights come from the AHN, which only covers the Netherlands. With our map builder you can still have a personalised 3D map made of any location in the Netherlands, Flanders and Germany.
Can I see my house in 3D?
Yes. Click 'See your street in 3D' and within a minute you'll see a 3D preview of your neighbourhood. You can order it as a framed 3D relief map for €49.