This document is intended to provide a comparison of two reports the 2021 IECC Residential Cost Effectiveness Analysis published for the National Association of Homebuilders (NAHB) by Home Innovation Research Labs (HIRL) in June 2021, hereafter referred to as the HIRL report1; and the report of the same name published by ICF in January 2022, hereafter referred to as the ICF report. The purpose of this document is to identify concerns and issues in the HIRL report, which were addressed in the ICF report.
