Alaska

Statewide summary — confirm with your building department before designing

No value on this row was changed by this audit. Alaska cannot be summarized by single numbers and these should be read as Southcentral and Interior placeholders. Seismic design category D reflects Anchorage, where short period design acceleration reaches about 1.0 g for Site Class D and the effective category is D2, and Fairbanks at about 0.73 g; Juneau computes to C and Ketchikan to B, so Southeast Alaska is lower. Ground snow load of 60 psf is not a statewide figure. Anchorage requires a minimum of 40 psf, while Valdez and other coastal mountain communities design for several hundred psf. Frost depth of 60 inches and a winter design temperature of minus 20 F sit between Anchorage, which is milder, and the Interior, which is far colder; neither could be matched to an adopted local table in this audit. The 130 mph wind speed is on the ASCE 7 ultimate scale, and the Aleutians and exposed coastal sites are considerably higher. Termite risk of none is correct. Permafrost and thaw settlement govern foundation design in much of the state and are not represented by any column here. Use the adopted criteria of your borough or municipality. 2026 snow-load pass. The framing that Alaska has no statewide building code for private residential construction is confirmed, but it is not the whole picture, and the state does have an adopted snow load table for the buildings it does regulate. Alaska Dept of Public Safety, Division of Fire and Life Safety adopts the International Building Code at 13 AAC 50.020, currently the 2021 edition effective Oct 28, 2022. The scope stated in the Division rulemaking notices is commercial buildings, assembly, educational and institutional residential facilities such as apartments and hotels, and high-impact facilities; one- and two-family dwellings are outside it, so a private house in an unorganized borough is governed by no state code at all and by whatever the borough or municipality has adopted. Within that scope, the adopted rule amends only Chapter 1 of the IBC and leaves Chapter 16 intact, so IBC Section 1608.2 and Table 1608.2, Ground Snow Loads for Alaskan Locations, are adopted state law for regulated buildings. snow_load_min_psf of 25 and snow_load_max_psf of 300 are the lowest and highest values in that adopted table: 25 psf at Barrow, Cold Bay and Shemya, and 300 psf at Whittier, with Valdez at 160, Petersburg and Yakutat at 150, Talkeetna at 120, Cordova at 100, Nenana at 80 and Anchorage at 50. Three caveats bound that range and matter more than the numbers. First, the table names only 33 locations. For any site not listed, Section 1608.2 does not give a number; it requires the ground snow load to be approved and based on an extreme value statistical analysis of data in the vicinity of the site at a 2 percent annual probability of exceedance, a 50-year mean recurrence interval. So 300 psf is the maximum of the tabulated locations and not a ceiling on Alaska, and the true statewide extreme in places such as Thompson Pass is higher. Second, the range applies only to Fire Marshal-regulated occupancies, not to private houses. Third, these are ground snow loads, not roof snow loads, and they sit on the ASCE 7-16 allowable-stress scale that the 2021 IBC uses; they must not be compared with strength-level values from ASCE 7-22 or converted. A sourcing disclosure: Alaska publishes the adopted amendments but not its own printing of the IBC text, and the Division PDF of 13 AAC 50 that was previously posted now returns HTTP 404, so Table 1608.2 was read from a government printing of the identical model section, the City of Seattle 2021 Seattle Building Code Chapter 16, and cross-checked line by line against the 2015 Seattle Building Code Chapter 16; the values are identical across both editions. No value on this row was changed. Ground snow load of 60 psf is retained and is now at least traceable: 60 psf is the adopted Table 1608.2 value for Fairbanks, Juneau, Fort Yukon, Galena, Kotzebue and Wrangell, though it remains an arbitrary choice as a statewide scalar, since Anchorage is 50 and Whittier is 300. Wind speed 130 mph, seismic design category D and frost depth 60 inches are unchanged and the caveats recorded above still stand.