THE HERS® INDEX AS A PERFORMANCE PATH TO BUILDING ENERGY CODES

The RESNET HERS® Index is the industry standard by which a home’s energy efficiency is measured. The HERS® or Home Energy Rating System was developed by RESNET and is the nationally recognized system for inspecting and calculating a home’s energy performance. Certified RESNET Home Energy Raters conduct inspections to verify a home’s energy performance and determine what improvements can be made to increase it. For more information click on RESNET HERS® Index

Across the nation state and local governments are adding a HERS® Index Score target as a performance compliance option to their building energy code.

The reasons why a HERS® Index Score is being tied into energy codes include:

• The inspection and testing protocols are established in RESNET’s national home energy rating standards. RESNET is a national not-for-profit membership standard setting organization. It is accredited by the American National Energy Standards Institute (ANSI) as a Standard Development Organization.
• The professionals that undertake the inspection and performance testing are certified following RESNET’s standards stringent training and testing procedures.
• All certified RESNET home energy raters are subject to RESNET’s quality assurance oversight procedures.
• The RESNET national home energy rating standards are recognized by the federal government (U.S. Department of Energy, Environmental Protection Agency, Internal Revenue Service) and the mortgage industry.
• The HERS® Index is a trusted measurement of the energy performance of a home. Over one million homes have been issued a HERS® Index Score in the US.

RESNET commissioned a study by the Florida Solar Energy Center on what HERS® Index Scores equates to the 2006. 2009 and 2012 versions of the International Energy Conservation Code (IECC) for typical residences across representative U.S. climates. This analysis will serve as an invaluable tool for local jurisdictions in assigning a HERS® Index Score for their energy codes and in the discussion of incorporation a HERS® Index Score in a future version of the IECC. To download the study click on Analysis of HERS® Index Scores for Recent Versions of the International Energy Conservation Code (IECC).

In October 2013 the International Code Council added an Energy Rating Index option to the 2015 version of the International Energy Conservation Code (IECC). The Energy Rating Index Option set the following scores as compliance to the 2015 IECC:

The 2015 IECC Energy Rating Index performance path also requires builders to achieve the mandatory code requirements of the IECC, follow hot water piping provisions and comply with the minimum insulation and window envelope performance requirements of the 2009 IECC.

To determine the cost effectiveness of the Energy Rating Index option of the 2015 IECC RESNET commissioned the Florida Solar Energy Center to conduct cost-effectiveness analysis of new homes configured to comply with the Energy Rating Index performance path provisions of the 2015 IECC[1] compared to homes configured to comply with the 2012 IECC. The analysis was conducted across all IECC Climate Zones with national averages weighted using new home construction starts. The study found that in all cases, compliance with the ERI performance path of the 2015 IECC is cost-effective.

• Annual savings of the 2015 IECC ERI performance path, averaged across climate zones, is $468.
• Life-cycle cost savings, averaged across climate zones, is $12,784 for the 2015 IECC ERI performance path.
• The Savings-to-investment ratio (SIR), averaged across climate zones, is 1.69
• The Net Present Value (NPV) averaged across climate zones, is $5,219

To down the analysis go to Cost Effectiveness of 2015 IECC Compliance Using the HERS® Index

The following jurisdictions have incorporated the RESNET HERS® Index Score into their building energy codes (click on the link to view):

https://www.energycodes.gov/adoption/states