Why Do Building Codes Matter for Insurance Supplements?
Building codes are the minimum construction standards that every roofing repair or replacement must meet. Unless there is an exclusion in the policy, when a storm damages a roof, the insurance claim should cover the cost of bringing that roof into compliance with the codes in effect at the time of repair.
This is where many claims fall short. Carriers often write estimates based on like-kind-and-quality replacement without accounting for code upgrades adopted since the roof was originally installed. A roof built in 2005 under the 2003 IRC likely needs significant upgrades to meet 2021 or 2024 code requirements.
For contractors and policyholders, understanding your state's current roofing codes is the foundation of a well-documented insurance supplement. Every code-required line item that gets left off an estimate is money left on the table.
What Is the Difference Between the IRC and IBC?
The International Residential Code (IRC) governs one- and two-family dwellings and townhouses. The International Building Code (IBC) covers commercial structures and larger multifamily buildings. Both are published by the International Code Council (ICC) and updated on a three-year cycle, with the most recent editions being 2021 and 2024.
Building departments do not automatically adopt new code editions. Each state, and sometimes individual counties or municipalities, must formally adopt a new edition through a legislative or administrative process. This means that at any given time, neighboring states, or even cities/counties may be operating under different codes.
The practical impact for roofing claims is significant. A home in Denver, CO may require different underlayment, fastener patterns, Ice and Water shield, or ventilation standards than an identical home 10 miles away in Golden, CO. Knowing which code version applies is the first step in building an accurate Xactimate estimate.
How Do States Adopt Building Codes?
States follow one of three adoption models. Understanding which model your state/municipality uses determines how much research each claim requires.
Statewide mandatory adoption means the state legislature or a state agency adopts a specific edition of the IRC/IBC, and all jurisdictions must enforce it.
Statewide adoption with local amendments means the state adopts a base code but allows cities and counties to add stricter requirements. Texas and California are prime examples.
Local adoption only means the state does not mandate a statewide code, and each city or county chooses whether and which code to adopt, making code research more involved on every claim.
State-by-State Roofing Code Breakdown
Below is a detailed look at roofing code requirements across 11 states where IA Solutions operates. Each section covers the adopted code version, key roofing provisions, and how those requirements translate into supplement line items.
Colorado
Adopted Code: 2021 IRC / 2021 IBC (statewide baseline, with local amendments)
Colorado presents one of the most complex code landscapes in the country. The state adopts a baseline code, but counties and municipalities frequently amend requirements based on local conditions. Areas along the Front Range, including Denver, Colorado Springs, and Fort Collins, often adopt stricter hail and wind provisions.
Key roofing requirements:
- Design wind speeds range from 110 mph to 130 mph depending on location and risk category
- Ice barrier (ice and water shield) required in areas where the average daily temperature in January is 25 degrees F or below, which covers most of the state
- Impact-resistant shingles (Class 4, rated under UL 2218) are not mandated statewide but are incentivized through insurance premium discounts in many Front Range counties
- Balanced ventilation required at a ratio of 1:150 of attic floor area, reducible to 1:300 when specific conditions are met
Supplement impact: Colorado claims frequently warrant line items for ice and water shield at eaves and valleys, upgraded underlayment, and enhanced fastener schedules for high-wind zones. Our Colorado team processes over a thousand of these supplements annually.
Texas
Adopted Code: 2021 IRC / 2021 IBC (statewide minimum, local adoption varies widely)
Texas is a home-rule state, meaning municipalities set their own building codes. Major metro areas like Dallas-Fort Worth, Houston, San Antonio, and Austin have adopted the 2021 codes, but rural counties may lag behind or have no adopted residential code at all.
Key roofing requirements:
- Design wind speeds vary dramatically, from 115 mph in North Texas to 160 mph or higher along the Gulf Coast (wind-borne debris regions)
- The Texas Windstorm Insurance Association (TWIA) imposes additional requirements in the first two tiers of coastal counties, including specific fastener patterns and product approvals
- Underlayment must meet ASTM D226 Type II (No. 30 felt) or equivalent in areas with design wind speeds above 120 mph
- Ice barrier requirements apply in the northern portions of the state where average January temperatures warrant it
Supplement impact: Coastal Texas claims require careful attention to TWIA compliance, including enhanced attachment schedules and approved product documentation. North Texas hail claims often involve code-upgrade line items for underlayment and starter strip requirements. Our Texas specialists handle both coastal wind and inland hail supplements.
California
Adopted Code: 2022 California Residential Code (CRC) / 2022 California Building Code (CBC), based on 2021 IRC/IBC with extensive state amendments
California maintains its own building code (Title 24) with amendments that often exceed IRC/IBC minimums. The state updates its codes on a triennial cycle, with the current edition effective January 1, 2023.
Key roofing requirements:
- Wildland-Urban Interface (WUI) zones require Class A fire-rated roofing assemblies, including fire-resistant underlayment and specific ridge and eave treatments
- Design wind speeds range from 110 mph to 130 mph, with higher requirements in desert and mountain pass areas
- Cool roof requirements (high solar reflectance) apply to low-slope roofing in Climate Zones 10 through 15
- Seismic provisions affect the attachment of rooftop equipment and heavy roofing materials like tile and slate
Supplement impact: California claims in WUI zones routinely require fire-rated assembly documentation and upgraded materials. Cool roof mandates in Southern California add material cost line items that carriers frequently overlook. Our California adjusters are experienced with Title 24 compliance documentation.
Idaho
Adopted Code: 2018 IRC / 2018 IBC (statewide)
Idaho currently operates under the 2018 code cycle. The state's adoption process is managed through the Idaho Division of Building Safety, and code updates tend to follow a slower adoption timeline.
Key roofing requirements:
- Design wind speeds generally range from 110 mph to 115 mph across most of the state
- Ice barrier required where average daily January temperature is 25 degrees F or below, covering the majority of Idaho
- Minimum underlayment of one layer of ASTM D226 Type I or ASTM D4869 Type I for asphalt shingle roofs
- Attic ventilation at 1:150 ratio, reducible to 1:300 with balanced intake and exhaust
Supplement impact: Ice and water shield is a frequent code-upgrade item on Idaho claims, especially for older roofs that were installed without it. Ventilation upgrades to meet current code also generate legitimate supplement line items.
Wyoming
Adopted Code: No statewide mandatory residential building code; local jurisdictions adopt codes individually
Wyoming is one of the few states that does not mandate a statewide residential building code. Municipalities like Cheyenne, Casper, and Jackson have adopted versions of the IRC (typically 2018 or 2021), but unincorporated areas may have no adopted code.
Key roofing requirements (where codes are adopted):
- Design wind speeds range from 115 mph to 140 mph, with extreme exposure areas in southeastern Wyoming exceeding 140 mph
- High-wind provisions including enhanced fastener schedules and specific underlayment requirements are critical in areas with sustained wind exposure
- Ice barrier requirements apply in adopted jurisdictions where January temperatures warrant it
Supplement impact: Wyoming's high wind speeds make fastener pattern upgrades and enhanced underlayment among the most common supplement line items. Documentation of the locally adopted code version is essential for claim support.
South Dakota
Adopted Code: No statewide mandatory residential building code; municipalities adopt codes locally
Like Wyoming, South Dakota leaves code adoption to local jurisdictions. Sioux Falls and Rapid City have adopted versions of the IRC (Sioux Falls uses the 2021 IRC), but many rural areas operate without a formal code.
Key roofing requirements (where codes are adopted):
- Design wind speeds range from 115 mph to 120 mph across most of the state
- Ice barrier is required at eaves in all adopted jurisdictions due to average January temperatures well below 25 degrees F
- Heavy snowfall areas in the Black Hills may trigger additional structural requirements for roof load capacity
Supplement impact: Ice and water shield at eaves, valleys, and around penetrations is a standard code-required line item across South Dakota. Ventilation upgrades are common on older homes that predate current balanced ventilation requirements.
Washington
Adopted Code: 2021 Washington State Residential Code (WSRC), based on 2021 IRC with state amendments
Washington adopts the IRC with state-specific amendments through the Washington State Building Code Council. The current edition took effect July 1, 2023.
Key roofing requirements:
- Design wind speeds range from 110 mph to 130 mph, with higher speeds along the coast and in mountain pass areas
- Ice barrier required in areas where average January temperature is 25 degrees F or below, primarily eastern Washington and mountain regions
- Western Washington's heavy rainfall zones require enhanced underlayment and flashing details per state amendments
- Energy code amendments may affect attic insulation requirements during re-roofing
Supplement impact: Western Washington claims often involve enhanced underlayment and flashing line items due to rain exposure. Eastern Washington claims typically include ice and water shield upgrades. Our Washington team understands the split between the state's two distinct climate zones.
Minnesota
Adopted Code: 2021 Minnesota Residential Code, based on 2021 IRC with state amendments
Minnesota enforces a mandatory statewide building code, with the current residential provisions based on the 2021 IRC. The Minnesota Department of Labor and Industry administers code adoption and enforcement.
Key roofing requirements:
- Ice barrier is required from the eave edge extending a minimum of 24 inches past the interior wall line on all roofs
- Design wind speeds range from 115 mph to 120 mph across most of the state
- Minimum two layers of underlayment or one layer of self-adhering polymer-modified bitumen for roof slopes between 2:12 and 4:12
- Attic ventilation requirements with specific provisions for cathedral ceilings and conditioned attics
Supplement impact: Minnesota's ice barrier requirements are among the most commonly underestimated items on carrier estimates. The 24-inch past interior wall line requirement often means 6 feet or more of ice and water shield at eaves, which significantly exceeds what many adjusters initially scope. Our Minnesota adjusters account for these extended coverage areas on every claim.
Ohio
Adopted Code: 2021 Residential Code of Ohio (RCO), based on 2021 IRC with state amendments
Ohio adopted the 2021 IRC as its residential code baseline, effective November 1, 2023. The Ohio Board of Building Standards oversees statewide code adoption.
Key roofing requirements:
- Ice barrier required where average daily January temperature is 25 degrees F or below, which applies across virtually the entire state
- Design wind speeds range from 115 mph to 120 mph
- Drip edge required at eaves and gable ends on all new shingle installations
- Flashing required at wall-to-roof intersections, chimneys, and all penetrations per manufacturer specifications
Supplement impact: Drip edge replacement and ice and water shield are the most frequent code-upgrade line items on Ohio claims. Many older homes lack compliant drip edge at gable ends, making this a legitimate code-required addition during re-roofing.
Oklahoma
Adopted Code: No statewide mandatory residential building code; municipalities adopt codes locally
Oklahoma does not enforce a statewide residential code, but major cities including Oklahoma City and Tulsa have adopted the 2021 IRC. Oklahoma City also maintains additional high-wind amendments.
Key roofing requirements (where codes are adopted):
- Design wind speeds range from 115 mph in eastern Oklahoma to 130 mph or higher in the western panhandle
- Oklahoma City amended codes require enhanced roof-to-wall connections and specific fastener patterns
- Impact-resistant shingles are not mandated but are incentivized through insurance premium discounts in hail-prone metro areas
- Underlayment and starter strip requirements follow the adopted IRC edition
Supplement impact: Oklahoma sees some of the highest hail claim volumes in the country. Code-upgrade line items for enhanced underlayment, starter strips, and proper fastener patterns are commonly supported in Tulsa and Oklahoma City supplement claims. Our Oklahoma team handles these high-volume markets daily.
Illinois (Chicago Metro)
Adopted Code: 2021 IRC statewide; City of Chicago maintains its own municipal building code
Illinois presents a unique situation. The state has adopted the 2021 IRC for residential construction, but the City of Chicago operates under its own municipal building code, which differs significantly from the IRC in several areas.
Key roofing requirements:
- Design wind speeds range from 115 mph to 120 mph across the state
- Ice barrier required statewide due to average January temperatures well below the 25 degree F threshold
- Chicago's municipal code includes specific roofing requirements for fire resistance and attachment that differ from the IRC
- Cool roof provisions may apply to certain commercial and multifamily buildings under Chicago's energy code amendments
Supplement impact: Claims within Chicago city limits require documentation referencing the municipal code rather than the IRC. Suburban claims follow the statewide 2021 IRC. Ice and water shield and ventilation upgrades are the most common code-required supplement items across the metro area.
Quick Comparison: State Code Adoption at a Glance
| State | Adopted Code Version | Ice Barrier Required | Design Wind Speed Range | Statewide Mandate | |-------|---------------------|---------------------|------------------------|-------------------| | Colorado | 2021 IRC/IBC | Yes (most areas) | 110-130 mph | Yes (with local amendments) | | Texas | 2021 IRC/IBC | Northern areas only | 115-160+ mph | No (local adoption) | | California | 2022 CRC/CBC (based on 2021) | Select mountain areas | 110-130 mph | Yes | | Idaho | 2018 IRC/IBC | Yes (most areas) | 110-115 mph | Yes | | Wyoming | Varies by jurisdiction | Yes (where adopted) | 115-140+ mph | No | | South Dakota | Varies by jurisdiction | Yes (where adopted) | 115-120 mph | No | | Washington | 2021 WSRC | Eastern WA and mountains | 110-130 mph | Yes | | Minnesota | 2021 MN Residential Code | Yes (statewide) | 115-120 mph | Yes | | Ohio | 2021 RCO | Yes (statewide) | 115-120 mph | Yes | | Oklahoma | Varies by jurisdiction | Where adopted | 115-130+ mph | No | | Illinois | 2021 IRC (Chicago has own code) | Yes (statewide) | 115-120 mph | Yes |
How Does Code Compliance Documentation Strengthen Your Supplement?
A well-documented supplement ties every line item back to a specific code requirement. This approach transforms a supplement from a negotiation into a compliance conversation. Carriers cannot reasonably deny a line item that is required by the building code in effect at the time of repair unless the policy has a specific exclusion.
The key documentation elements include the specific code edition adopted by the jurisdiction, the relevant code section numbers, product data sheets showing compliance with referenced standards (like ASTM D226 or UL 2218), and photos showing existing conditions that do not meet current code.
When your supplement package includes a jurisdictional code reference alongside your Xactimate line items, you give the reviewing adjuster a clear, defensible basis for approval. This is the approach our licensed adjusters use on every claim we handle.
What Happens When You Miss a Code Upgrade?
Missing a code upgrade on an insurance claim means the contractor absorbs the cost. The roof still has to be installed to current code. The building inspector will not sign off on an installation that falls short of adopted standards, regardless of what the insurance estimate says.
On a typical residential roof replacement, missed code upgrades can total $2,000 to $4,000 or more. That includes items like drip edge at eaves and rakes, ice and water shield extending past the interior wall line, ventilation additions to meet the 1:150 NFA ratio, and enhanced fastener schedules for high-wind zones.
These are not optional add-ons. They are code requirements that insurance policies with ordinance or law coverage are designed to pay for.
What Should You Do Next?
Navigating building codes across multiple states is one of the most time-consuming parts of writing accurate roofing supplements. Code versions change, local amendments add complexity, and carriers frequently push back on items that are clearly code-required.
IA Solutions operates in all 11 of these states and more. Our team of licensed Independent Adjusters brings 5 to 15 or more years of experience to every claim, and we maintain current code reference libraries for every jurisdiction we serve.
If you are a contractor dealing with underpaid roofing claims, our residential supplement service handles the code research, Xactimate estimating, and carrier negotiation so you can focus on the work. We also provide standalone Xactimate estimates for contractors who need accurate, code-compliant scope documentation.
Contact us today to discuss your next roofing claim. We will show you what code-backed supplementing looks like.