The U.S. Department of Energy (DOE) encourages greater energy efficiency in residential buildings through the development and implementation of model energy codes. In support of this goal, the Department assesses the savings associated with updated editions of the International Energy Conservation Code (IECC), the national model energy code for residential buildings. DOE relies on an established methodology, and conducts both national and custom state-level analyses. In addition, a State Savings Calculator allows for further customization based on various economic perspectives and other state-level assumptions.

National Analysis

Pacific Northwest National Laboratory (PNNL) assesses recent editions of the IECC to quantify the associated energy & cost savings. This analysis confirms the cost-effectiveness of updated editions of the model codes in prominent building types across U.S. climate zones, and is of interest to policymakers, as well as adopting states & localities. The following national analyses are currently available:

• Cost Effectiveness of the 2015 IECC
• HERS Index Values Corresponding to the IECC

State Analysis

PNNL also conducts analysis to assess savings and cost effectiveness within individual states. These analyses are customized based on current state energy codes, and take into account varying state-level conditions, such as incremental costs, utility rates and construction trends. The table below contains reports covering the various state scenarios based on the 2015 IECC.

State Savings Calculator

The State Savings Calculator provides a means of further tailoring state-level cost-effectiveness analysis. This interactive tool mimics the overall DOE methodology, but allows for customized economic assumptions and other parameters that may vary on a state-by-state basis. These include parameters such as local cost adjustments, energy prices and escalation rates, inflation and taxes, loan terms, and the overall study period used for the analysis. A report can also be generated that summarizes results in a format similar to the official PNNL state analysis reports.

Download the residential state savings calculator: Version 1.0 – Revision 1 (February, 2016)
Note: The calculator is based in Microsoft Excel. Macros must be enabled for proper functioning. It is recommended to open the calculator in a separate instance of Excel.

Energy & cost savings analyses for previous editions of the IECC are also archived.