Most roofing professionals understand a building's roof assembly serves an important
role in controlling a building's overall energy efficiency and building owners'
heating and cooling costs. However, some may not realize that codes mandate minimum
thermal insulation requirements for the energy efficiency of most buildings.
Energy conservation codes usually are adopted by individual states and are applicable
to all buildings within that state. Most states have adopted one of several editions
of the International Energy Code (IECC), published by the International Code Council
(ICC), to serve as the technical basis of their energy codes. In some instances,
individual states modify the IECC to address specific regional or local issues.
To assist roofing professionals, NRCA compiled a database of states' current energy
code adoption. This information was obtained either from individual states' Web
sites or the Department of Energy's "Energy Code's Program's" website,
. Users are encouraged to contact the
government agency having jurisdiction to verify the specific energy code(s) applicable
to their projects.
Click here to access NRCA's database of energy codes by state
EnergyWise Roof Calculator Online
IECC provides two methods of determining commercial buildings' minimum insulation
requirements: the use of specific tables within the Code or compliance with American
Society for Heating, Refrigerating and Air-Conditioning Engineers Inc. (ASHRAE)
Standard 90.1 (ASHRAE 90.1), “Energy Standard for Buildings Except Low-Rise Residential
Buildings,” building envelope provisions.
If you want to determine minimum R-value requirements per ASHRAE 90.1, you should
consider using EnergyWise Roof Calculator Online.
NRCA, in partnership with The Roofing Industry Alliance for Progress developed EnergyWise
Roof Calculator Online, developed this free, Web-based application based in part
on the Prescriptive Building Envelope Option contained in ASHRAE Standard 90.1,
versions 1999(2001), 2004 and 2007.
EnergyWise Roof Calculator Online also provides a graphical method of constructing
roof assemblies to evaluate thermal performance and estimated energy costs under
normal operating conditions. This application is intended to be a simplified guide.
For complex energy evaluation calculations, consult the ASHRAE Fundamentals Handbook
or an experienced mechanical engineer.
Click here to access EnergyWise Roof Calculator
Roofing-related Energy Code Requirements
If you want to become more familiar with roofing-related energy code requirements,
you are encouraged to read "Conserving energy" by Mark Graham, NRCA's Associate
Executive Director of Technical Services. This article provides an overview of energy
codes' minimum requirements and how these requirements apply to existing buildings
Click here to access
In addition, NRCA offers Guidelines for Complying With Energy Code Requirements for
Roof Assemblies: International Energy Conservation Code, 2009 and 2012 Editions
for sale in the NRCA Bookstore. This publication provides a step-by-step guide for
complying with the requirements of the International Energy Conservation Code's
(IECC's) 2009 and 2012 editions and ASHRAE 90.1, "Energy Standard for Buildings
Except Low-Rise Residential Buildings," 2007 and 2010 editions, which are referenced
in IECC's 2009 and 2012 editions, respectively.
Click here for more
information or to purchase Guidelines for Complying With Energy Code Requirements
for Roof Assemblies: International Energy Conservation Code, 2009 and 2012 Editions.