Purpose

This policy resolves a conflict between differing seismic design category classifications for Monroe County found in Table R301.2(1) and Figure R301.2(2) of the 2020 Indiana Residential Code.

Background

The 2020 Indiana Residential Code, which went into effect on December 26, 2019, incorporates and amends the first printing of the 2018 International Residential Code for One- and Two-Family Dwellings. See 675 IAC 14-4.4. Table R301.2(1) and Figure R301.2(2) of the 2020 Indiana Residential Code both provide the Seismic Design Category Classifications for all 92 counties in Indiana and are intended to mirror each other, however, these two items provide conflicting classifications for Monroe County.

Table R301.2(1) of the 2020 Indiana Residential Code, which was amended from its original form in the 2018 International Residential Code, places Monroe County in Seismic Design Category C. See 675 IAC 14-4.4-5 which is attached to this document as Exhibit A. Figure R301.2(2) of the 2020 Indiana Residential Code, which is unamended for the 2018 International Residential Code, places Monroe County in Seismic Design Category B. A copy of Figure R301.2(2) is attached as Exhibit B. The purpose of listing the specific Seismic Design Categories in Table R301.2(1) is to reproduce the visual classifications provided for in Figure R301.2(2) in a more easily discernible written format. However, as explained above, when Table R301.2(1) was transcribed, Monroe County was mistakenly placed in Seismic Design Category C. In order to resolve this conflict, the Fire Prevention and Building Safety Commission adopts the below interpretation.

Interpretation

Figure R301.2(2) of the 2020 Indiana Residential Code controls the appropriate Seismic Design Category classification of Monroe County, not Table R301.2(1). Therefore, Monroe County is classified in Seismic Design Category B.