The 2015 International Residential, Building, Plumbing, Mechanical, Fuel Gas, Energy Conservation and Existing Building Codes as amended by Larimer County will go into effect for all permits initiated on or after May 1.
To view the new Larimer County residential and non-residential building code amendments, go to larimer.org/building/ and click on the first item under “Hot Topics” at the top of the page. You can also pick up copies of the amendments at the Larimer County Building Department offices in Fort Collins and Estes Park.
Some of the most important changes include:
Snow load design: Based on a review of what Larimer County says is the best available data, including a 2015 statewide study by the Structural Engineers Association of Colorado, the county has designated 35 pounds per square foot as the minimum design ground snow load for roofs on buildings constructed on land up to 5,000 feet in elevation. Those numbers increase to 45 PSF for elevations of 5,001 to 6,000 feet, 50 PSF from 6,001 to 6,500 feet, 60 PSF from 6,501 to 7,000 feet and 70 PSF from 7,001 to 8,000. Engineering design is required for roofs built at elevations above 8,000 feet. Roof load reductions are still allowed in line with standard engineering practice, but the minimum design roof load will be 30 PSF.
Wind load design: The terminology used to designate wind loads, and the method of calculating wind loads, has changed over the last few code cycles, causing some confusion. However, the county says wind load design has not increased. County maps, tables and certifications designate ultimate wind loads wherever possible. But as of May 1, Larimer County’s High Wind Design table (“Building Geometry Limitations”) will be deleted. The Wood Frame Construction Manual will be the accepted method for high-wind design. In general, where ultimate wind speeds exceed 140 mph, engineered design will be required. Note: Pole barns and loafing sheds can still be built per Larimer County Prescriptive Design Limitations.
Noncombustible siding and landscaping in the Wildfire Hazard Area: To reduce fire spread from burning embers settling on grass or shrubs next to combustible siding, ground cover and siding for new construction in the Wildfire Hazard Area will need to be noncombustible for a minimum of 3 feet out and 3 feet up from where the walls meet the exterior grade.
Garages, shops, barns and other utility structures: These buildings must be at least 6 feet away from a dwelling, or have standard fire-resistance requirements (minimum of 1/2-inch gypsum on walls and 5/8-inch Type X on ceiling, with self-closing fire doors). Structures larger than 5,000 square feet that are within 6 feet of a dwelling must have a minimum one-hour rated Fire Containment Assembly.
Building permits: Permits won’t be required for replacing nonstructural siding, shade cloth and maximum 6-mil poly-roofed private greenhouses, bridges and culverts constructed under other county engineering permits, and solar systems installed on structures that don’t need a permit (like sheds under 120 square feet).
Prescriptive insulation requirements: These requirements will remain at 2009 levels, and a Res-Check submittal showing compliance with the 2009 International Energy Conservation Code will be deemed to meet code. Air leakage tests are still required for new residences.
Sprinklers: Sprinklers aren’t required for new residences, nor is gypsum protection for the underside of I-joists.