Thursday, August 31, 2017

First Web Map with Carto!

I built my first interactive web map using Carto! (I normally use Mapbox or Leaflet). The Sightline Institute asked me to create an updated version of a map they made a few years back that shows the average price of Single Family and Multi-Family homes by neighborhood. When you zoom into a neighborhood, it shows the location and sale price of every individual transaction.

Click here to read the article, and click here to go directly to the map.

There was a significant amount of data prep to get the King County Assessor data working properly, but the results are pretty stunning, as demonstrated by this quote:

In fact, across the city multi-family home sales averaged $220,000, or 30 percent, less than average single-family home sales over the last year. Even brand new multi-family homes, those built within the last 18 months, cost an average of $45,000 less than older single-family homes, those built prior to 2016.

One of the biggest technical challenges for me on this project was figuring out how to incorporate Google Street View images into the pop-up. I solved it by generating lat/long coordinates for the centroid of each parcel, then I used my API key to call for the streetview photo that corresponds to that location.