Iowa Ground Snow Load: What the Adopted Code Carries

Iowa adopts the national building code without a ground snow load amendment of its own, so the governing figure for a given address is the one the code's own table carries, and the body that applies it is the local jurisdiction, through its building department where it has established one. 17 states are in the same position, which makes it the second commonest arrangement in the country. Iowa publishes ground snow loads through the local jurisdiction, through its building department where it has established one, and the jurisdictions reached for this had put none into a public document at the time they were read.

The local jurisdiction, through its building department where it has established one: the state adopts the national code without filling in any snow figure, and the jurisdiction where the work is enforces it. In its own words: “481—300.6(103A) Local code enforcement. Provisions of the state building code applicable statewide or applicable in a local jurisdiction that has adopted the state building code by local ordinance may be enforced by the local jurisdiction.”

Department of Inspections, Appeals, and Licensing, State Building Code Commissioner adopts International Residential Code, 2024 edition (residential); International Building Code, 2024 edition (all other construction) (2024 edition). Iowa adopted it as written. The adopting rule reads: “481—301.8(103A) Residential construction requirements. The provisions of the International Residential Code, 2024 edition, published by the International Code Council, located at www.iccsafe.org, are hereby adopted by reference as the requirements for construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal, and demolition of detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories in height with a separate means of egress and their accessory structures, with the following amendments:”

A ground snow load is a weight per unit area and not a depth, and the two are joined only by the density of the snow on the day, which is why the published documents give the load and leave the depth out. Wet spring snow and dry January snow of the same depth are different weights on the same roof. The local jurisdiction, through its building department where it has established one works in loads for that reason, and so does every figure set out below.

The code's figure is applied to a given address by the local jurisdiction, through its building department where it has established one. The document behind it is 481 Iowa Administrative Code Chapter 301, State Building Code, rule 481-301.8(103A), subrule 301.8(3), published by Department of Inspections, Appeals, and Licensing, read on September 23, 2026. It establishes the point this way: “301.8(3) Note: The values for Table R301.2 are determined by the location of the project and referenced footnotes from Table R301.2.”

14 of 50: Connecticut, Indiana, Maryland, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New Jersey, North Carolina, Rhode Island, Utah, Vermont, Wisconsin. The other 36 split into 17 that adopt the national code without a snow amendment and 19 that leave every figure to a county or city building department. That is the single most useful fact about this subject and no one state's own website carries it.