Thornton, Colorado
Window work in Thornton
Thornton's median year built is 1997, and the single largest decade is 2000 to 2009. The window aging out of that stock is the original insulated glass, not a prewar wood sash like the ones covered in window repair in Arvada.
Housing age in the census
| Built | Units | Share | Margin of error |
|---|---|---|---|
| 2020 or later | 1,995 | 3.8% | plus or minus 342 |
| 2010 to 2019 | 7,674 | 14.7% | plus or minus 578 |
| 2000 to 2009 | 13,665 | 26.2% | plus or minus 839 |
| 1990 to 1999 | 10,383 | 19.9% | plus or minus 740 |
| 1980 to 1989 | 7,093 | 13.6% | plus or minus 673 |
| 1970 to 1979 | 6,926 | 13.3% | plus or minus 656 |
| 1960 to 1969 | 1,992 | 3.8% | plus or minus 464 |
| 1950 to 1959 | 2,261 | 4.3% | plus or minus 293 |
| 1940 to 1949 | 107 | 0.2% | plus or minus 101 |
| 1939 or earlier | 154 | 0.3% | plus or minus 104 |
Source: U.S. Census Bureau, table B25034 and table B25035, Thornton city, Colorado. The Census Bureau does not record window frame material.
The city has 52,250 housing units. The 2000s account for 13,665 (26.2%), the 1990s for 10,383 (19.9%), the 2010s for 7,674 (14.7%), and the 1980s for 7,093 (13.6%). The 1950s are 2,261 units (4.3%). Houses from 1939 or earlier are 154 units, 0.3%. Units built in 2020 or later are already 1,995, 3.8%.
Climate from Stapleton, with the airport to the east
Thornton does not have its own filled-in normals station in the set used here. Denver Stapleton (USW00023062) is about 10 miles south: annual average 50.2 F, 15.58 inches of precipitation, 53.8 inches of snow, elevation about 5,286 feet. Denver International Airport (USW00003017) is about 16 miles east: annual average 50.5 F and 14.30 inches of precipitation, at about 5,414 feet. Thornton sits between a 15.58 inch record and a 14.30 inch record. Neither instrument is in Thornton.
Hail and wind in the NOAA storm file
The place name Thornton is on 8 hail reports from 2015 through 2024. The largest is 1.75 inches on 30 May 2024. Adams County has 135 hail reports in the same years, with a maximum of 2.75 inches at Brighton on 18 June 2018. Brighton is the neighboring city, not a Thornton address.
One thunderstorm wind report names Thornton: a measured gust of 53 knots, about 61 mph, on 24 June 2020. The high wind zone for central and east Adams and Arapahoe counties has 12 events and a measured gust of 59 knots, about 68 mph, on 17 April 2018. The zone that names west Adams County has 28 events and a measured gust of 80 knots, about 92 mph, on 6 April 2024.
Permits in Thornton
Thornton's permit list says replacement of windows and doors requires a building permit, and so does installation of additional windows or doors. Glass replacement within the existing sash or frame does not. The list is the city's projects that require a permit file. A homeowner rapid-review sheet updated 20 February 2026 includes window and door enlargement and replacement among residential alterations the city will try to review quickly. That sheet is posted here. Applications go through the CityView portal described on the building permits page. The Building Division phone on that page is 303-538-7250.
This is a reading of Thornton's posted lists, not a permit issued by the city.
Sources
- Census B25034, Thornton city
- Census B25035, Thornton city
- NOAA normals, Denver Stapleton USW00023062
- NOAA normals, Denver International Airport USW00003017
- NOAA U.S. Climate Normals
- NOAA Storm Events Database
- NOAA storm events bulk files
- Thornton permit list
- Thornton rapid review list
- Thornton building permits
Services covered for Thornton
- Window replacement cost ranges for the Denver metro
- Window installation for new openings and basement egress
- Window repair for fogged glass, hail cracks, and hardware
- Window cleaning for glass, screens, tracks, and hard water
Questions
When was most of Thornton built?
The 2024 American Community Survey 5-year estimate gives Thornton city a median year built of 1997, margin of error 1 year, and 52,250 housing units. The largest decade is 2000 to 2009, at 26.2% of units.
Does Thornton require a permit for window replacement?
Yes. The city's permit list includes replacement of windows and doors, and installation of additional windows or doors. Replacing glass inside the existing sash or frame does not require a permit. Homeowner window enlargement and replacement is on the rapid review list updated 20 February 2026.
What is the largest hail report NOAA filed at Thornton?
From 2015 through 2024, eight hail reports use the place name Thornton. The largest is 1.75 inches on 30 May 2024. Adams County's largest report in that file is 2.75 inches at Brighton.
How windy is the NOAA record near Thornton?
A measured thunderstorm gust of 53 knots, about 61 mph, is logged at Thornton on 24 June 2020. The high wind zone for central and east Adams County shows a measured gust of 59 knots, about 68 mph, on 17 April 2018. The zone that includes west Adams County shows 80 knots, about 92 mph, on 6 April 2024.
Nearby cities
Directory
No Thornton street address in the snapshot
The 22 August 2026 directory tags Denver, Aurora, Lakewood, Arvada, and Westminster. It does not publish a Thornton street address, so this page does not invent one. A listing is not an endorsement.
Thornton replacement costs
Vinyl, fiberglass, and wood installed ranges for the Denver metro, with insert and full-frame explained.