If you don’t read Austin Contrarian there is a really good set of articles over there about weighted density. Basically, instead of just dividing the total number of people into the total area in which they live, you cut the area into slices, find the density of each slice, then average the slices based on how many people live in each.
To put it another way, suppose you select a person at random from a metropolitan area. How dense is their neighborhood? An average of these values would constitute weighted density, and would in turn provide an insight into how the average person lives.
If you followed the comments in my earlier post, I sort of guesstimated a population density of 6000 people per square mile inside Beltway 8, a commenter pointed out that it was more like 3900, and I realized that I was mentally excluding the large undeveloped areas as well as the substantial industrial development that exists along the Ship Channel.
Weighted Density provides a way to quantify that earlier guesstimate, by excluding those vast uninhabited areas. And whaddaya know. From a recent Contrarian post, here’s Houston and Austin:
Density hovers in the low 6000s as you travel outside Midtown and through the Montrose and the First through Fourth Wards. It drops to 5000 as you pick up the lower densities of large-lot neighborhoods like MacGregor, River Oaks, and the Heights. Then the density picks back up again as you get outside of the prewar gridded neighborhoods and into the land of large garden apartment complexes, which are some of the densest tracts in the city. Houston is level at about 6,000 people per square mile out to about 12 or 13 miles before steadily falling.
In other words, out to about Beltway 8.
Now rarely is the question asked,
is our children learning why is Houston so much denser than Austin, given that Austin’s original housing stock was of the same basic type as Houston’s? The most simplistic answer is that Houston has just built a lot more multifamily housing, whether that’s greenfield garden apartments in Gulfton or Westchase or infill garden apartments in the Montrose or infill condos along Memorial and in Uptown and varying other places.
Austin, on the other hand, has tended to follow the more traditional American path of restricting everything to single-family at initial buildout, then later having awkward conversations and long and drawn-out meetings asking “where shall we increase density?” If you read the Austin Contrarian archives you’ll learn all about the VMU ordinance and exceptions to the VMU ordinance and neighborhood-by-neighborhood infighting over who’ll be “forced” to accept density. Against all this, one little fight over one Ashby high-rise seems like child’s play by comparison.