Kendall County, IL Roof Snow Load - 20 psf
How much snow is too much for a roof in Kendall County, IL?
20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Kendall County to carry. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 20 psf - higher than the 17.5 psf the ground-load formula alone would give, and the code says use the larger one.
Picture it, not just weigh it: 44 in. if it's fresh powder, 16 in. once it settles, or a mere 4 in. if it's ice. This is a meaningful design load - most modern-code homes handle it fine, though an addition, a carport or a flat-roofed section can be a weak spot.
Kendall County at a glance
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#621 of 2,758
- Illinois rank#14 of 102
- Population143,171
- Annual snowfall, NOAA normal29.2 in.
- FIPS17093
How Kendall County compares
20 psf ranks #621 of 2,758 US counties with a mapped snow load (top 23%) - and #14 of 102 in Illinois. Illinois counties average 19.3 psf; Kendall County runs 0.7 psf higher than that.
Population 143,171 (FIPS 17093), roughly 41.5881°N 88.4306°W. The 25 psf ground snow load ASCE 7-22 maps here becomes 20 psf once the code's own design factors are applied.
Typical snowfall in Kendall County, IL
NOAA's 30-year normal for Kendall County: 29.2 in. of snow a year, from the PLAINFIELD 3 NE, IL US station. (fresh vs. packed vs. ice explains why.)
What this Kendall County figure assumes
This is a county-level reference figure for a typical heated home built to Risk Category II (ordinary residential), on a partially exposed lot - the assumptions ASCE 7-22 itself treats as the default case. A steeper roof, a fully exposed hilltop lot, an unheated structure, or a higher risk category all change the actual number.
Kendall County's permit office wants an address-specific figure, not this county average - the ASCE 7 Hazard Tool is free, takes under a minute, and outputs a PDF most reviewers accept. (How this figure is calculated.)