The newest housing in Collin County, and its own mold problems
Frisco is the youngest big city on our list. The Census Bureau’s July 2025 estimate puts it at 236,955 residents, up 18.2% since 2020, and the ACS 2024 5-year survey gives a median year built of 2009 across 77,208 occupied homes. Only 1.5% of those homes predate 1980, and 65.9% are owner-occupied.
That means almost no cast-iron drains or asbestos ceiling texture. It also means two-story plans with the air handler in the attic, builder-grade flashing, big roofs that took hail on April 11, 2016 (Frisco was one of the four cities hardest hit, with Plano, Wylie and Allen), and attic water lines that froze when DFW hit minus 2 °F on February 16, 2021.
Frisco sits about 12 miles northwest of central Plano and spans Collin and Denton counties. The mold rules are the same on both sides; permits are not.