Every building in America

In the Oct. 12th 2018 NY Times an article titled “A MAP OF EVERY BUILDING IN AMERICA” was published. I thought, WOW! that’s pretty sweeping, I wonder if it is true. Here’s a tinyurl link to the article: http://tinyurl.com/ycrl23ce

In the article they describe what they did and provide links to the source data so I downloaded the data and winnowed it down to Windham. That’s usually the first thing to do with Big Data – make it as small as possible. Of course it is not a map of every building, but what they did and how they did it is a good piece of work and one can learn a bit from the article.

Loading the data into a gis application ( plug for QGIS.org ) and comparing their results to Vermont’s 911 data we can see that they miss quite a few Windham buildings.

This first map is of their data and southern Vermont.

NY Times data of southern VT and the boundary of Windham
NY Times data showing buildings with Windham

And the last image shows both data sets – the Times data in black squares and VT data larger transparent circles.

NY Times data overlaying VT 911 data.
Times is black and VT is transparent circles.

So one can see that a lot was missed by the Times approach. To be more exact, the Times data shows 296 buildings and the VT 911 data shows 472.