Dashboard week kicked off today with instructions to use Domain Group’s free API to find real-estate data on agents or property listings. Domain’s API documentation is comparatively comprehensive so it wasn’t long before we were sending POST requests in Alteryx to build a query similar to one you may enter on Realestate.com.au to refine a search.
I recently moved from Newcastle to the Inner West of Sydney and, although I’m no longer bitter at the price of my dwelling, it was a no brainer to analyse rental prices for listings near me. Specifically, I wanted to know how different each listing price was from the 2016 median rent amount for the corresponding suburb.
Getting the data
I used a post request to retrieve data from all property types within the Inner West. The listing limit per page is 200 and an overall limit of 1000 is enforced for the free API so I requested 200 listings 5 times and unioned these. A batch macro would have been a more elegant alternative, but macros aren’t my strong suit and I wanted a relatively small dataset quickly.
Into Tableau
My first iteration of the visualisation used colour to highlight whether each listing exceeded or fell below the median weekly rent for it’s suburb. This didn’t show any trend, likely because the number of bedrooms wasn’t considered, so median weekly rent per suburb was swapped for the median prices of 1,2,3 and 4+ bedroom properties across the whole Inner West LGA.
This change started to tell a different story, mainly that the Eastern Inner West suburbs have a higher proportion of listings that exceed the 2016 median rent for properties with a corresponding number of bedrooms.
To be sure of this I added a stacked bar chart to the tooltip of each post code boundary.
What’s causing this difference?
My first hypothesis was that these suburbs may have simply had higher median rents even in 2016. It was important to check this as the data I used to get median prices by property size were constant across all post codes of the Inner West. Looking at the spread of weekly median rents in 2016 however, it appeared that some of 2016’s higher rent municipalities (Drummoyne, Canada Bay, Abbotsford and Mortlake) held a lot of Domain listings that fell below the median weekly price. Hunting down the median rent prices for each post code by number of bedrooms would shed more light on this very preliminary investigation.
Reflections
- Blending ABS data into an investigation is interesting but hard to draw insights from.
- Dashboard week is super fun.
- The Inner West looks like a giant bunny with floppy ears.
