Ventilation Code Requirements in Indiana

State with significant severe hail frequency per NOAA SPC storm reports. Insurance restoration contractors should document pre-existing hail damage and recommend impact-resistant materials.

Indiana Department of Homeland Security (IDHS) Division of Fire Prevention and Building Safety has jurisdiction over design release for Class 2 structures (all buildings except 1-2 family dwellings). State review required before local permits. Local jurisdictions cannot waive this requirement.

Indiana allows local jurisdictions to adopt and enforce building codes for Class 1 structures (1-2 family dwellings). NOT all Indiana jurisdictions have adopted residential building codes. Verify local requirements before any residential project. Indianapolis (Unigov/Marion County), Fort Wayne, Evansville, South Bend and most urban areas have local enforcement.

Indiana Energy Conservation Code applies statewide regardless of whether the local jurisdiction has adopted other building codes. Based on IECC with Indiana amendments. Applies to all new construction, additions, and some renovations. Climate Zones 4A (southern) and 5A (northern/central).

Prefabricated and modular buildings in Indiana require IDHS approval and certification. Industrialized Building Systems must comply with Indiana IBS rules. Inspection at factory by IDHS-approved agency. Indiana insignia required on compliant units.

Karst terrain affects multiple counties in southern Indiana beyond the major karst counties listed separately. Additional counties with karst features include: Harrison, Washington, Martin, Greene, Owen, Jackson, and portions of others. Karst development varies from minor (occasional sinkholes) to major (extensive cave systems). The Mitchell Plateau, Crawford Upland, and Norman Upland are the primary karst physiographic regions.

FEMA-designated Zone AE (Special Flood Hazard Area with established Base Flood Elevations) is present along major river corridors throughout Indiana. Primary flood zones along: Ohio River (entire southern border), Wabash River (western Indiana), White River (central Indiana including Indianapolis), Whitewater River (eastern Indiana), St. Joseph River (northern Indiana), Kankakee River (northwest), and numerous tributaries. Indiana participates in NFIP (National Flood Insurance Program).

Indiana Dunes National Park (formerly National Lakeshore, designated National Park in 2019) spans Lake, Porter, and LaPorte counties along 15 miles of Lake Michigan shoreline. The park includes beaches, dunes, wetlands, prairies, and forests. Private property exists within park boundaries (inholdings). Development restrictions apply to areas adjacent to park.

Ice barrier underlayment is REQUIRED statewide per Indiana Building Code (IRC R905.1.2). Indiana spans Climate Zones 4A (southern) and 5A (central/northern). Mean January temperatures range from 28°F (Evansville area) to 23°F (South Bend/lake effect zone). Indiana receives 25-70 inches of snow annually.

State within or adjacent to the tornado corridor. NOAA SPC data confirms significant tornado frequency. Enhanced structural requirements apply per IRC R301.2.1.2.