To achieve the economic, environmental, and social benefits offered by energy codes, a state or jurisdiction must select the energy code that is most appropriate for their locale. States and municipalities generally choose to either adopt a model energy code or standard or create a state-specific or local energy code. States or municipalities may also select to adopt "stretch codes"—those that go beyond the minimum requirements of an adopted energy code to achieve greater energy efficiency. In addition, states and local jurisdictions may choose to adopt policies that implement a green building rating system or policies that apply to specific structures, such as state-owned or –funded buildings.
Model Energy Codes and Standards
Model energy codes and standards are created nationally to set minimum requirements for energy-efficient design and construction. The two primary national model energy codes that states may adopt as a baseline for the new construction or renovation of residential or commercial buildings are the IECC and ANSI/ASHRAE/IES Standard 90.1 (ASHRAE Standard 90.1), Energy Standard for Buildings Except Low-Rise Residential Buildings.
The IECC is developed by the ICC and provides energy efficiency guidelines for all residential and commercial buildings. The newest version of the code, 2012 IECC, was published in May 2011. When adopted and implemented by states, the 2012 IECC is estimated to result in a 30% increase in energy efficiency over the 2006 IECC.6
ASHRAE Standard 90.1 is developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) and provides energy efficiency guidelines for all commercial buildings, defined as buildings other than single-family dwellings and multifamily buildings three stories or less above grade. The newest version of that standard, ASHRAE Standard 90.1-2010, was published in August 2010. When adopted and implemented by states, ASHRAE Standard 90.1-2010 is estimated to result in an 18.2% savings in energy cost when compared to ASHRAE Standard 90.1-2007.7
There are several advantages to adopting a national model energy code or standard. Both the IECC and ASHRAE Standard 90.1 offer design and construction guidelines based on regional climates, providing states and jurisdictions with viable building techniques calculated for their specific needs. Additionally, each code and standard is developed and amended in open public forums through a consensus process. (See Resource 1 at the end of this step for more detailed information on how the IECC and ASHRAE Standard 90.1 are developed.) Updates to the model codes and standards occur regularly with stakeholders and industry leaders collaborating to incorporate the newest technologies, processes, and materials into each updated version. Model energy codes are vetted by industry professionals and provide states and jurisdictions the infrastructure and support for successfully adopting, implementing, and enforcing an energy code.
The ICC has generated a comprehensive toolkit to assist states in adopting the IECC and other International Codes® (I-Codes®). The Code Adoption Toolkit includes support material that covers adoption, technical issues, and advocacy. In addition, the ICC provides code adopters with sample policy ordinances for the adoption of the 2006 IECC, 2009 IECC, and 2012 IECC. See Resource 2 in this step for ICC adoption ordinances.
Similarly, ASHRAE provides guidance to states and jurisdictions through advocacy support, education, and technical assistance. Like the ICC, ASHRAE offers states a number of model legislation templates tailored to the needs of the jurisdiction. Policies can be found for states or jurisdictions adopting a code for the first time or looking to update an existing energy code to the latest version (Resource 3 in this step).
It is generally recommended that model energy codes and standards be adopted without amendments. Unamended adoption provides states with full access to the resources available through the ICC and ASHRAE, as well as access to the tools and resources developed by DOE's BECP (Resource 4 in this step). As a result, states and jurisdictions save the valuable resources, including time and money, expended when developing a state-specific or local code.
It is not always feasible, however, to adopt a national model energy code. In these situations, states and jurisdictions may choose to adopt a national model code by reference and then amend the code or develop a state or local code that better fits their specific energy goals.
State-Specific Energy Codes
State-specific energy codes are generally developed by states that find portions of the model energy codes inapplicable to their energy goals or needs and, as a result, adopt model codes by reference only. As such, states choose which requirements will be mandatory and amend the model energy code to better reflect their energy goals. See Resource 5 in this step for guidance on amending energy codes.
In some instances, however, states or jurisdictions adopt codes that are developed entirely from scratch. Washington and Oregon are two examples of states with state-specific, state-written codes (see Resources 6 and 7 in this step for more information).
Stretch Codes or Locally Adopted Codes
Some states, counties, and cities are now adopting beyond-code programs or stretch codes—codes that go beyond the minimum code required for all buildings in a state. In some states that do not adopt a minimum code, any code adopted at the county or city level could be considered a stretch code by this definition. In other states that do adopt relatively energy efficient codes, such as Massachusetts and Oregon, stretch codes represent an opportunity to require even better buildings.
States and jurisdictions may choose to adopt a national model green code, such as the International Green Construction Code (IgCC). Most above-code programs or stretch codes use IECC and/or ASHRAE Standard 90.1 as a baseline and include requirements that replace or expand the corresponding requirements.
For example, if the IgCC is adopted as a stretch code, it is assumed that a building will comply with the IECC and then go beyond that code to meet the additional requirements of the IgCC. Similarly, if ANSI/ASHRAE/USGBC/IES Standard 189.1 (ASHRAE Standard 189.1) is adopted as a stretch code, it is required that the building comply with ASHRAE Standard 90.1 and then go beyond that standard to meet the additional requirements of ASHRAE Standard 189.1. See Resources 8, 9, and 10 in this step for information on where stretch codes are in use, but also plan on checking with local code officials.
States and jurisdictions may also elect to create a beyond-code program rather than adopt and implement a national model green code. The "Going Beyond Code Guide" (Resource 11 in this step) will help state and local governments design and implement successful beyond-code programs for new commercial and residential buildings. The goal of the guide is to help states and localities establish voluntary or mandatory programs that go well beyond traditional minimum code requirements for new buildings. The guide addresses keys to successful adoption and implementation and discusses the primary areas that are typically included in beyond-code or green building programs, including energy efficiency materials and resource conservation, water efficiency, indoor environmental quality, and site development and land use. Detailed descriptions and analysis of actual programs are discussed, including lessons learned and best practices. States and localities can use the information on local programs, national codes and standards, and the model energy efficiency criteria for residential and commercial buildings to find the best approach for their jurisdiction to develop and implement an effective beyond-code program.
Green Building Rating System
Many projects are being designed under green building rating systems such as the USGBC's LEED rating system, the Green Building Initiative (GBI) Green Globes rating system for commercial buildings, or the National Green Building Standard (ICC 700) for residential structures. The use of green building rating systems may be voluntary or mandatory.
Green building rating systems are intended for buildings that are being designed "better than code" and as such, minimum energy codes are met before points are awarded for improved energy performance.
See Resources 12 and 13 in this step for information on where prominent green building rating systems may be required. Key national programs and examples of how they have been adopted include:
- Home Energy Rating System. Commonly known as HERS, this rating system compares the energy efficiency of a home to a computer-simulated reference house. The rating involves analysis of the home's construction plans and at least one on-site inspection. This information is used to estimate the home's annual energy costs and give the home an index rating between 0 and 100. The lower the score, the more efficient the home. Jurisdictions such as Boulder County, Colorado, have mandated a particular HERS index for new residential construction.
- ENERGY STAR®. ENERGY STAR homes are typically 15% more energy efficient than homes built to average minimum energy codes. The U.S. Environmental Protection Agency outlines criteria for ENERGY STAR certification of homes and commercial buildings. New York State allows local jurisdictions, such as Brookhaven, to adopt ENERGY STAR as their minimum residential energy code.
- EarthCraft. Developed by Southface Energy Institute in partnership with the Building America Program, EarthCraft House is a point-based program that includes ENERGY STAR certification and 2006 IECC in its baseline. The program is used in Alabama, South Carolina, Tennessee, Virginia, and Georgia. The City of Nashville also offers incentives for EarthCraft homes.
- Collaborative for High Performing Schools. This rating system mandates energy efficiency levels 25% above ASHRAE Standard 90.1-2004. Originally a California standard, it is being revised for regional factors and adopted by states and school districts across the country.
- Green Points Rating System. Green Points exceeds the 2005 California Energy Code Title 24 by 15%. Build It Green/Green Points is a membership supported non-profit organization used by jurisdictions as a mandatory or voluntary third-party certification program. Numerous jurisdictions throughout California have adopted it. In Santa Clara County, for example, the system is mandatory for all homes above 1,200 ft2 that are not LEED for Homes.
- National Association of Home Builders (NAHB) Green Guidelines. These guidelines are 15-40% above 2003 IECC or local code. First published in 2005, the NAHB Model Green Home Building Guidelines were written by a group of builders, researchers, environmental experts, and designers to provide guidance for builders engaged in or interested in green building products and practices for residential design, development, and construction. The guidelines were also written to serve as a "baseline" so that NAHB members could easily develop local programs. Local jurisdictions and utilities promote the program and provide verification, such as in Pierce County, Washington.
- ASHRAE Standard 189.1. Developed in conjunction with the Illuminating Engineering Society (IES)—previously known as the Illuminating Engineering Society of North America (IESNA)—and the USGBC, ASHRAE Standard 189.1 applies to new commercial buildings and major renovation projects and addresses energy efficiency, the impact of a building on the atmosphere, sustainable sites, water use efficiency, materials and resources, and indoor environmental quality. ASHRAE Standard 189.1 was developed for inclusion into building codes.
- LEED. LEED for New Construction and Major Renovation requires a minimum 10% compliance beyond ASHRAE Standard 90.1-2007. Developed by the USGBC, LEED is a green building certification system, providing third-party verification addressing energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, and stewardship of resources and sensitivity to their impacts. There is a suite of LEED programs focused on various building types or stages of occupancy. Many federal agencies, states, and local jurisdictions have mandated or encouraged LEED certification for municipal buildings. Local jurisdictions, such as Rohnert Park, California (mandatory) and Charlotte County, Florida (voluntary) have incorporated LEED into their codes.
- International Green Construction Code. IgCC was developed in conjunction with the American Institute of Architects (AIA) and the American Society for Testing and Materials (ASTM). lgCC is coordinated with the other ICC model codes and is intended for adoption and use with those codes. It provides criteria for site development and land use, material resource and conservation, energy efficiency and air quality, water resource conservation, indoor environmental quality, and building operation and maintenance, as well as provisions for existing buildings. The document also provides adopting agencies with a variety of provisions upon which they can base their adoption to best address their energy needs. The IgCC references ASHRAE Standard 189.1 as an acceptable path to compliance.
- ICC 700-2008 National Green Building Standard. ICC 700-2008 exceeds the 2006 IECC by a minimum of 15%. This standard defines green building for single and multifamily homes, residential remodeling projects, and site development.
Progressive states and jurisdictions are beginning to select outcome-based energy codes to achieve energy efficiency goals. Unlike traditional codes in which a building or home is compared to a theoretical baseline, outcome-based codes measure actual energy use once a building is occupied, commissioned, and operating. Outcome-based codes are then satisfied not only through energy-efficient design and construction, but through operational and tenant energy use as well. Resource 14 in this step, the New Buildings Institute (NBI), offers guidance and numerous resources on outcome-based codes, including their development and adoption.
It is important to select an energy code that will achieve the goals established by a specific state or jurisdiction in the most efficient way possible.
Many states choose to adopt a model energy code because they are developed by industry professionals and do not require additional state or jurisdiction resources to create.
Model energy codes should be adopted without amendments for total access to resources. For greater energy savings, consider the adoption of a green building code or beyond-code program. If a statewide green building code is not feasible, allow counties or municipalities to enforce a local green building program.
- Building Energy Codes 101: An Introduction 
- Model ICC Adoption Policies 
- ASHRAE Model Legislation 
- DOE's BECP Resource Center 
- To Amend or Not to Amend National Model Energy Codes and Standards 
- Oregon Energy Code 
- Washington State Energy Code 
- DOE's Building Energy Codes Program Status of State Energy Codes Database 
- ICC's Adoption Database 
- BCAP Status of State Energy Codes 
- Going Beyond Code: A Guide for Creating Effective Green Building Programs for Energy Efficient and Sustainable Communities 
- USGBC List of Public Policies Adopting or Referencing LEED 
- GBI Map of States with Laws Recognizing Green Globes 
- Outcome-Based Energy Codes 
- International Code Council Government Relations Code Adoption Toolkit 
- OCEAN Codes and Voluntary Programs 
- OCEAN Policy Action Tool 
- EPA Sustainable Design and Green Building Toolkit for Local Governments 
- Developing Green Building Programs: A Step-by-Step Guide for Local Governments by Global Green USA 
- 2011 Midwest Regional Building Energy Codes Conference 
- Halverson, M., B Liu, M. Rosenberg. 2011. ANSI/ASHRAE/IES Standard 90.1-2010 Final Determination Quantitative Analysis . Pacific Northwest National Laboratory, Richland, Washington.