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BACKGROUND: Building Code 101 

Every three years, after extensive committee meetings, public hearings, and on-line voting by building  code officials across the U.S. to consider proposed changes, the International Code Council (ICC) publishes a new edition of the model building codes (International Building Code, Residential CodePlumbing Code, etc.) Local jurisdictions, including Larimer County, review these new codes along with  engineers, architects, homebuilders, and other interested stakeholders and propose local amendments  to make the codes work best for them. Local amendments may add, delete, or change proposed code  sections. When elected officials vote to adopt these amended codes, they take effect as local  ordinances.

The first adopted building code in Larimer County – the 1970 Uniform Building Code – took effect on  January 1, 1972. Almost all new code editions have been adopted since then. Over the years, the  Larimer County Building Division has worked with neighboring jurisdictions like Fort Collins, Loveland,  and Estes Park to try to adopt the same code with similar amendments. This year, the Chief Building  Officials of many northern Colorado jurisdictions met often to try to coordinate building code adoption  more closely, leading to a joint Fort Collins/ Larimer County 2021 Code Review Committee meeting  every Tuesday from 10 am to 1 pm in Spring and Summer.  

To better inform the review committee’s work and engage interested stakeholders in these  deliberations, Larimer County Chief Building Official is seeking your opinion on a series of questions  related to the 2021 code update. He has tried to determine what issues will most concern the public. If  there are other code issues you would like to weigh in on, or simply have question or general  comments, we’d love to hear them.  

Navigating the Questions 

You can pick and choose which ones you would like to respond to. You don’t have to answer them all.  If you don’t have an opinion, skip that one and move on.  

Feel free to answer anonymously. However, if you’d like to participate in any webinars or open houses,  or want someone to contact you, please provide your name and contact information at the end. 

Where to Find More Information and How to Get Involved 


For several code cycles now, the International Residential Code (for one- and two-family dwellings, townhouses, and their accessory buildings) has required fire sprinklers for all new dwellings. Larimer County and some jurisdictions have removed the sprinkler requirement when adopting the code. Other jurisdictions have required sprinklers for townhouses and duplexes only. Should Larimer County:
For many commercial uses (“occupancies”) the International Building Code (IBC) requires either fire sprinklers or that Fire Areas (the area between fire walls, fire barriers or floor-ceiling assemblies) are no greater than 12,000 square feet. By local amendment, Larimer County, Fort Collins, and Poudre Fire Authority have lowered the allowable, non-sprinklered Fire Area to 5,000 square feet maximum. The lower limit keeps fires contained until firefighters can arrive, but it conflicts with national code rules and can add costs. Should Larimer County (select preferred option):
For the last two decades, Larimer County has amended its residential and commercial building codes to include additional requirements in the wildfire hazard area. These amendments include defensible space around structures, minimum Class B fire-rated roofing and minimum Class C fire-rated siding, spark arrestors on chimneys and noncombustible ground cover or siding at grade. Some jurisdictions have adopted the International Wildland Urban Interface Code (IWUIC) and its additional requirements, but Larimer County has not. Should Larimer County (select preferred option):
Under Colorado state law, the International Fire Code (IFC) takes effect within a county when adopted by a fire district and approved by the County Board of Commissioners. In Larimer County, Wellington, Poudre, Loveland, Berthoud, Windsor-Severance, Estes Park and Lyons Fire Districts have adopted Fire Codes. Everywhere else, including commercial areas in Red Feather and along the Poudre River, the Fire Code does not apply. Certain Fire Code requirements (like sprinklers, fire alarms and exiting) which are also in the Building Code are enforced by the Building Division, but others (tent permits, fire access roads, high-piled storage, for instance) are not. (See Fire Districts map here.) Should Larimer County (select preferred option):
After extensive public engagement, in the 2018 code cycle the Town of Estes Park and Larimer County created a series of building code life-safety rules for Vacation Homes in the Estes Valley. Both the Town and County also adopted Land Use Code rules and procedures for Vacation Homes. Later amended and extended countywide for STRs, these rules allow transient rental homes to be regulated under the residential code and not require sprinklers or accessibility. However, STRs must get planning approval, building permits and inspections. Life-safety requirements include bedroom emergency escape openings, smoke and carbon monoxide alarms, fire extinguishers, utility shutoffs, operation manuals and signs. Owner-occupied lodging houses with no more than five guest rooms and Resort Lodge Cottages do not have to meet the life-safety rules. (Large STRs and owner-occupied lodging houses fall under the IBC commercial building code.) These rules are unique to Larimer County. Some other jurisdictions treat STRs like regular single-family homes, while others treat them like small hotels. Some residents think our rules are too strict, while others think they are too lax. Opinions vary from allowing STRs as a use by right with no permitting needed, to prohibiting them entirely. In the Estes Valley, there is an overall cap on STRs in residential zoning districts, and concern over county Land Use Rules limiting STRs to one per property. Going forward, Larimer County plans to regulate all new transient rental homes under STR guidelines and require new small owner-occupied lodging homes and resort lodge cottages to comply with the most critical life safety rules as well. Should Larimer County (select preferred options):
Public interest in Tiny Homes has grown substantially in recent years. Customers frequently ask about county rules for Tiny Homes, which we regulate under our Land Use Code (Section 3.3.5. E.) as Recreational Vehicles (RVs) if they are still on wheels. If someone wants to build a Tiny Home on site, place it on a permanent foundation, and get every stage of construction inspected, we can permit it like any other house, just smaller. (Larimer County has adopted 2018 International Residential Code Appendix Q, which offers more flexibility for Tiny House construction.) However, prefabricated Tiny Homes moved onto a lot cannot legally be permitted as buildings by Larimer County, unless they were built in a state approved manufactured or modular home factory. The Colorado Division of Housing has declared that these homes fall under their jurisdiction and cannot be placed on a permanent foundation because neither state nor local authorities have performed required construction inspections. The Colorado Plumbing and Electrical Boards have said these homes may not be connected to the utility grid for the same reason. As a statutory county, Larimer County lacks the regulatory flexibility that home rule cities and charter counties enjoy. State law may need to change, or an industry-wide Tiny Home standard may need to be approved before we can resolve this dilemma. Should Larimer County (select preferred option):
The 2021 International Energy Conservation Code (IECC) requires continuous wall insulation as well as wall cavity insulation, R-60 (instead of R-49) ceiling insulation, R-30 floor insulation, and R-10 slab insulation four foot down from the top of at-grade slabs (instead of two feet), among other changes. More energy efficiency improves occupants’ health and comfort, saves money over time, and helps stabilize our climate to prevent excessive warming. Increased requirements may raise housing costs for too little benefit and restrict homeowners’ choices. Continuous insulation will require changes to how walls are framed, especially attaching siding through foam board while resisting high winds. Over the last few code cycles, Larimer County has adopted the most current energy codes while amending them slightly to loosen the requirements. Fort Collins has adopted energy and sustainability code amendments that go beyond the IECC. State law requires any jurisdiction adopting a building or energy code to adopt one of the three most recent energy codes. The energy codes, federal and state law, and city and county policy are all moving towards Net Zero Energy Use within a relatively short time frame. Do you (select preferred option):
The IECC energy requirements apply to all building that are heated or cooled (“conditioned”). By local amendment to IECC Section 101.2, Larimer County allows detached accessory residential and agricultural buildings with 2-hour or less timers or 50 degree temperature limits to not have to comply with energy code rules. They can also meet lesser requirements including R-13 wall and R-30 roof insulation. Some of these buildings contain a mix of residential (office, writer’s studio, workout room) and utility (garage, shop, barn) uses. Perhaps the residential space should follow the same energy code rules? Should Larimer County (select preferred option):

Note: Larimer County is also reviewing how we regulate Accessory Living Areas  under our Land Use Code Phase 2 Update. For more information, see 



Rooftop (and ground-mounted) residential solar PV systems are becoming more common as their price comes down relative to other forms of electricity generation, public concern about climate change rises and governments from the local to the federal level plan to transition to a low-carbon future. The International Residential Code and the National Electrical Code (Article 690) contain rules to make sure the installation is safe for homeowners as well as firefighters who may need to be on the roof in case of fire. These rules include electrical safety, structural integrity of the roof, fire classification of the panels, setback from ridges and access pathways from eaves to ridge. To promote solar PV installations, permit fees are capped by state law to $500 for residential systems. Fort Collins, Longmont, Boulder and other Colorado cities and counties have joined SolSmart’s list of “Solar Friendly Communities” and Fort Collins has streamlined permit application requirements. Fort Collins has also adopted a building code amendment (Section E3401.6) requiring new homes to be “photovoltaic ready” by installing an empty metal conduit from the attic underneath the most likely roof plane to the electrical panel or a junction box near the electric meter. Should Larimer County (check all that apply):
Larimer County’s location along the Rocky Mountain Front Range provides serious climate challenges: extreme winds, heavy snows, high wildfire danger and severe hailstorms. Larimer County requires minimum Class B fire- rated roof coverings in the Wildfire Hazard Area, Class C elsewhere. Most common roof coverings meet or exceed these minimum requirements, except untreated wood shakes and shingles, which are prohibited. Fort Collins (which is outside the designated Wildfire Hazard Area) requires all roof coverings to be at least Class A. According to the Insurance Information Institute, Colorado has the second most hail loss claims in the US, trailing only Texas. Fort Collins requires new asphalt shingle roof coverings to be Class 4 impact-resistant (the highest rating by Underwriters Laboratory), which costs about 10-20% more according to shingle manufacturers, but which last longer, resist hail damage and reduce maintenance costs. Should Larimer County require (select all that apply):
Radon, a naturally occurring radioactive gas that comes from the breakdown of uranium in the soil, is the second leading cause of lung cancer in the US, according to the Surgeon General. Larimer County has high naturally occurring radon levels, above the public health threshold for concern (4.0 picocuries per liter). For decades, most new homes in Larimer County whose lot went through a subdivision process have been required as a condition of planning approval to install a passive radon mitigation system during construction and test for radon prior to obtaining a certificate of occupancy. A passive system - a PVC or ABS pipe collecting soil gas under the basement slab or crawl space vapor barrier, extended through the roof with a junction box in the attic for a possible future fan – is simple and cheap to install during new construction, harder to install during a retrofit. The radon test lets the homeowner know how high their specific indoor radon level is so they can decide if they want to make their system active by installing an in-line exhaust fan. Larimer County has adopted International Residential Code Appendix F as an installation guide for radon systems. Should Larimer County (select all that apply):
The building codes require permits for swimming pools greater than two feet deep to prevent drowning and other hazards, especially for small children. The International Swimming Pool and Spa Code (ISPSC) contains detailed regulations for swimming pools, diving pools and spas, both public and private. Larimer County has not adopted the ISPSC, instead adding pool barrier requirements (fencing, pool covers and/or door alarms) and suction entrapment avoidance to our adopted building codes (IBC Section 3109). The ISPSC also contains design requirements for public pools (at motels, campgrounds, HOA pools, etc.) as well as general requirements for plumbing, heating, electrical, and other safety features. Fort Collins and many other jurisdictions have adopted the entire ISPSC. Should Larimer County (select preferred option):