Full disclosure: The Tim is employed by Redfin.
With the latest monthly stats release from Redfin going live a couple days ago, I thought I would spend a little more time with the data (in addition to all the on-the-clock time I spent this week getting it prepared for release).
In order to make the numbers in the spreadsheet more digestible, I thought a Tableau map would be just what the number doctor ordered (big surprise, I’m sure). In the map below each zip code with enough sales in June is shown as a dot, with the size of the dot determined by the number of sales in that zip code in June. Each dot is color-coded based on whichever measure you select below the map. You can view the month-over-month or year-over-year changes in inventory, sales, median prices, or median prices per square foot.
[Update: By request, I have modified the color coding on the map below to a more colorblind-friendly palette.]
As you can see if you leave the map on its default setting, house sales took a tumble from May to June in most Seattle-area neighborhoods, but were slightly up month-to-month on the Eastside. I suspect with the (original, unextended) expiration of the tax credit at the end of June, next month that version of the map will see an awful lot more dots.
Interestingly, if you look at the raw median price year-over-year, you’ll see a fair bit of green in the central Seattle area, but if you flip the measure to the median price per square foot, much of that green turns to gray or red. This would seem to suggest that prices have actually fallen in many of these neighborhoods over the last year or so, but buyers are just purchasing bigger houses.
Let me know what you think of this method for visualizing Redfin’s housing market data. One thing that has always frustrated me about the available information has been that it was difficult to see how the market was changing from neighborhood to neighborhood. With Redfin’s data broken out by zip code, I think the ability to make a heat map like this goes a long way toward improving understanding of what’s really going on, but I’m interested to hear your feedback as well.