Visualizing and Comparing Residential Permit Data Using Lollipop Plots

Alexander Din
U.S. Department of Housing and Urban Development

The views expressed in this article are those of the author and do not represent the official positions or policies of the Office of Policy Development & Research, the U.S. Department of Housing and Urban Development, or the U.S. Government.

Residential permits are a common indicator of housing market activity. Residential permits indicate the demand for new homes, and by categorizing homes into different construction types, it is possible to understand what types of homes are in-demand in the market and the types of homes that the market is producing. In this article, I use a cross between a scatter plot and a bar chart called a lollipop plot to visualize residential permits by year for single-family dwellings (SFDs) and townhomes in Montgomery County, Maryland. These data were obtained from dataMontgomery (2019), the open data portal for the county. These data are for construction permits that were finalized between 2000 and 2018 for SFDs and townhomes, as far back as data were available. Between 2000 and 2018, there were 14,831 and 6,322 permits for SFDs and townhomes, respectively.