Small submarkets tend to see bigger percentage apartment growth rates due to their relative size, but eight large submarkets across the country saw their existing apartment count increase by 50% or more during the past five years, according to a RealPage report.

The Avondale/Goodyear/West Glendale submarket of Phoenix had the largest percentage inventory change over the past five years, growing 116.7% to 32,641 units this year. The markets are all located within Maricopa County, one of the fastest-growing counties in the country between 2020 and 2024. By comparison, apartment inventory across the country increased by 11.3% during this time frame, and the Phoenix market had average growth of 21.5%, said RealPage.

Second on the list is the East Austin submarket of Austin, Texas, which had 30,571 units at the beginning of this year, up 92.5% from 2020. It was one of five states' submarkets that made the list and one of two Austin submarkets. The other is Round Rock/Georgetwon, which placed fourth on the list, with apartment inventory growing 69.9% to 32,646 units. Overall, Austin’s apartment inventory grew 33.3% over the past five years, the fastest in the nation, as it saw a notable increase in the renter-age population drawn in part by its growing appeal as a tech hub.