Building ages in the Netherlands | Hacker News Reader

Building ages in the Netherlands

parallel.co.uk

237 pointsSchiphol49 comments

For those who are curious, the building age data comes from the Dutch government (as others already said). It was imported into OpenStreetMap about 5 years ago by a few dozen volunteers including myself.

The data contains addresses and buildings (outline, building started date, and an identifier to make updates easier). This means we removed all existing buildings and addresses in the country, which felt really risky, but because the import was done manually and only tool-assisted, it seems we managed to get it right. Took a few months, but once enough volunteers hopped on, it went quite fast. If I remember correctly, once you got the hang of it (your third import or so), an average municipality took about 2 hours (we have 350 municipalities).

For the Dutch speakers among us, more info about the project can be found here: https://wiki.openstreetmap.org/wiki/NL:BAG

I am not sure where Mapbox' height data comes from. In OSM, you can give a "levels" tag to indicate how many levels a building has (from which the height can be estimated), or a height tag in meters if it is known, but the buildings don't have that. Perhaps it is just assumed that large buildings are a bit taller and building=house is an average house height unless otherwise noted? Or maybe they use the Dutch AHN, which is a very accurate height scan of the Netherlands. Some people made it into a 3d picture, e.g. https://snipboard.io/Sq6C38.jpg (this only uses AHN data, not OSM, so it only has the tops of objects as points, but that's still quite an accurate outline).

To be more precise: it was imported en masse once, and has been meticulously maintained via localised imports ever since. OpenStreetMap in the Netherlands shows how open data can flourish when volunteers and government collaborate.

Back when I was at Mapbox and we were developing the library used for this sort of visualization, I did a take on my home city of Portland, OR in a similar fashion:

https://blog.mapbox.com/visualizing-an-entire-citys-building...

(Disclaimer: some of the images, and especially the code formatting, don’t seem to have survived very well)

I wrote there a bit more about the data processing side of this, and I tried to make a compelling mobile visualization that was fast. I’d use it a lot for demo and pitch-type meetings, and especially with an HDMI connector direct from iPhone to a 50, 60 or 70” display, the frame rate and fluidity was super impressive.

To this day, I just plain love the tech that we built.

Impressive visualisation. Seems to be an extrusion of the Kadaster (government) building data towards the maximum height of the structure.

Much more precise data is also also available: there are height maps of NL with a resolution of 5 points per square meter, IIRC (not my field). Eg [1], but perhaps more parties do similar work.

[1]: https://ahn.arcgisonline.nl/Postcodetool/s2.html?app=Postcod...

And as mentioned elsewhere, they indeed misrepresent renovations & construction work as building dates.

And even better, you can view the underlying data as a 3d point cloud here: (crashed my Firefox on mobile) http://potree.entwine.io/data/ahn.html

Cute, but riddled with errors. In my area (Arnhem / Nijmegen) it assigns 1975 as the date for buildings that are much newer. It also sets my house as 1925 when 1900 would have been more accurate (it was, however, split in 2 around 1920 or so - maybe that’s where the confusion comes from?)

Happy to report that in my area (The Hague) it seems to be very accurate.

Can confirm. The building where I live, and my office building (both in the Hague) are spot on.

They didn't create the dataset. The dataset is from the government's Basisregistratie Adressen en Gebouwen (BAG).

If you spot errors, contact your local municipality, since they provide this data to the central registry.

It's possible they're misinterpreting the dataset.

In my case, the dataset is wrong. My entire neighbourhood was built in 1987, and my house had extensive renovations in 2010. Now my house is marked as being built in 2010. Oddly, pretty much every house in the neighbourhood has had some big renovation or other, but only mine and one other one ("2008") have the wrong date in the registry.

I'm not going to correct it, because it doesn't matter.

They do indeed seem to use the last time something significant was added to a building, which leads to strange dates such as a 19th building around the corner from where I live getting reported as 1983 because that, apparently, is when they added the hideously ugly front portal to it.

Strange thing is, they're inconsistent about it. De 1914 building De Vereeniging is listed as 1914 even though they've at the very least added a large conservatory to it since as well as a humongous - and very ugly and cheap looking - backstage area (though that was only this year, so maybe that hasn't ended up in the data set yet).

Oh well ...

> I'm not going to correct it, because it doesn't matter.

It does matter (although it is possible you simply don't care). This data is used for a lot of purposes, which may include the calculation of your house's estimated worth for taxation.

Most municipalities do appreciate the feedback via https://bagviewer.kadaster.nl. A more accurate public dataset benefits society as a whole.

This is the official viewer by the creators of the dataset, Kadaster (our land registry office): https://bagviewer.kadaster.nl/lvbag/bag-viewer/index.html#?g...

And the best ways to get rid of these errors is to visualize them like done here!

My Utrecht house is marked as 1888 but the facade has an ornament that says 1898. Very close still.

There is similar one for Katowice, Poland: http://katowickiebudynki.eu/ (2d, with Leaflet.js)

...and the downvote if for?

(I am not related to the project above, just in case.)

TIL my house was built in 1338. I honestly had no idea.

It's a mark of distinction to live in a house that old. You should be proud!

I'm just sad it's 1 year off from 1337, to be honest.

you could say it's better than l33t

Very impressive visualization, works smoothly even on a mid range Android phone.

Yeah, this is cool stuff.

It feels similar to me to OSMand+ (an open alternative to the very laggy Google Maps).

OsmAnd+ isn't open (it has a proprietary licence), but the source of the map data (OpenStreetMap) is.

There seems to be a free software alternative for OsmAnd+ called OsmAnd~ by the way:

https://en.wikipedia.org/wiki/OsmAnd#Licensing

The non-premium version called OsmAnd seems to be FOSS too.

Does someone knows wich 3D API there are using ? - BabylonJs (guess?) [could explain the smooth visualisation] - another one ?

I believe they used Mapbox for both the basemap and 3D visualisation

https://docs.mapbox.com/mapbox-gl-js/example/3d-buildings/

Thank you

Very much worth viewing in relation to the effects of WW2 http://googlemapsmania.blogspot.com/2014/04/amsterdam-during... with https://maps.amsterdam.nl/woii/ being the one you want.

I thought of https://en.wikipedia.org/wiki/German_bombing_of_Rotterdam first.

Here's the St. Lawrence church from the first picture of the article: https://parallel.co.uk/netherlands/#15/51.92139/4.485/0/40

Go look at downtown Rotterdam if you want to see the effects of WWII.

Which effects? Amsterdam wasn't heavily bombed in WW II. Although Rotterdam certainly was and Arnhem was heavily damaged as part of Operation Market Garden.

Yes, this was my thought as well. I was in Rotterdam last summer which was mostly leveled by WWII bombing. It was very striking how much more modern the city was than cities like Amsterdam which came away with much less destruction. Obviously the destruction was horrible, but it was really interesting to me how it paved the way for redevelopment and vibrant newness. I guess this should be obvious. The chain of cause and effect is very straightforward and unsurprising in retrospect. But somehow at the same time it also seems counterintuitive how destruction can enable advancement.

For those who missed the description on the webpage, the data that is visualized is called "3D BAG", which we get by combining the "BAG" (buildings) and the "AHN" (point cloud) data sets. The 3D BAG (http://3dbag.bk.tudelft.nl/) is created by the us at the 3D geoinformation group (https://3d.bk.tudelft.nl/).

It's got my house dated incorrectly. Looks fancy though.

Got mine right

Yea I was wondering this, the house I was born in is in a street of mostly 1920's houses, and then one corner house is from 1875, doesn't seem right to me. 99% else seems right though, really fun to look trough

You can look up the source data here:

https://bagviewer.kadaster.nl

It is possible to provide feedback there; your local municipality will look into any feedback provided.

Pretty impressive. But it would be nice if you could turn-off certain era's to see how an area evolved.

Have a look at https://www.topotijdreis.nl/ here they layer old maps going all the way back to 1815.

That reminds me of a scene in Clarke’s novel “The City and the Stars”, where there is a map that lets one view the entire billion year history of the city of Diaspora. I thought that was a cool idea when I read the book decades ago and now we can actually do it!

Rotterdam, which was bombed during WW2: https://parallel.co.uk/netherlands/#13.49/51.91912/4.48476/8

The colors for "really old" and "unknown" shouldn't be so similar.

A lot of houses in Amsterdam date from around the same time as the founding of New Amsterdam

The buildings are shown in 3D, but it seems it is only a 2D representation + height.

Hell of a lot easier to generate, and to render.

Is that base layer something which is standard in OSM and how do I get it?

No, the data is from official government sources. OSM data is good, but mostly not that good in comparison with official sources.

It's a custom Mapbox GL style (clear in the page source). I'm not sure if it is related to one of the Mapbox default styles.

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