Saturday, August 31, 2013

Mapping Out Real Estate Sales

I talked about this map on a recent podcast and wanted to share it here as well. If you click on it, you should get to see the large version of it. It's meant to be printed on a 17"x11" sheet of paper.

This map shows sales in Corvallis, Albany, Lebanon and Philomath in the last 12 months. People often talk about price differences in Corvallis and Albany, and this map shows it perfectly. Of course, this map takes it a another step and shows the differences in neighborhoods too. Often North Albany is said to be more expensive, and South Corvallis is thought to be less expensive. With the map, you can clearly see that.

What's also fun is finding the place you recently bought or sold on the map. We bought two in the last 12 months and I was able to pick them out (one yellow and one green dot).

I don't know if this will become a regular thing, but it sure was fun to make once I figured out all the tools I needed to combine to make it happen.

Want to make a map yourself? Here's how to do it:

  • I created a grey map using MapBox. They have all sorts of cool styles to choose from. It requires a free account.
  • I installed an app of their's called TileMill. It took a while to figure out how to use this. It's not as intuitive as I would like.
  • I imported a reference layer from map I made in MapBox to TileMill (under setting, link to your map's MapBox ID).
  • Then, I went to the MLS database and exported all the sales in the last 12 months, including their price. This could, in theory, be anything geographic.
  • I went to GPS Visualizer and geocoded all the address (1,700 of them!) to latitude and longitude using their javascript tool.
  • Once I had that, I made a .CSV file of the data and imported that into TileMill as another map layer.
  • TileMill is cool because then I could style the markers any way I wanted using code similar to CSS. I chose plain dots that differed in color based on the price. I could also change the size of the dots if I wanted based on some other criteria.
  • Then I created a 17"x11" image at 300 ppi in Pixelmator. This is like Photoshop for Mac, but much more affordable and just as powerful in my opinion.
  • Then it was a laborious task of taking screen shots of TileMill, cropping them down to only the map using Mac's build in Preview app and lining up the layers in Pixelmator. Since a screen's resolution is 72 ppi, I essentially had to blow everything up 3 times the size so it printed normally. I had more than 30 layers to cover the entire canvas.
  • I couldn't fit Lebanon inline with the other cities, so I broke it out into it's own box. It happens.
  • I could also, if I wanted, upload my dots layer back to MapBox and then have something to embed on a website. Like so:

So there you go. A cool map that shows sales and a really quick guide on how to make it. Or at least, the tools to make it happen.

No comments:

Post a Comment