Building Design, Energy Codes and

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Energy efficiency codes and standards for new buildings are the most cost-effective ways to improve the efficiency of a new building. Improvements can be made when a building is being designed and constructed at a fraction of the cost that it would take to make similar improvements once it is built. Energy codes require all new buildings to be built to a minimum level of energy efficiency that is cost-effective and technically feasible. Considering the average lifespan of a building, investments in energy saving technology ultimately pay for themselves many times over.

Building codes play a role in supporting the welfare of the community. They protect life, health and safety. They also protect the investment that has been made by bankers, insurance companies, businesses, and individuals. Finally, building codes promote economic development by protecting the value of the built environment.

This section will discuss the history of building construction regulations, the role of energy in building construction regulations, how these regulations have evolved into our current system, and the future of building construction regulations and energy.


The need to develop standards, codes, and other rules for the design, construction, operation, and maintenance of buildings has been driven over the years by a number of factors. These factors include comfort, fire safety catastrophic events, egress, sanitation, and health, among others. The first recorded building code was that of the Amorite king, Hammurabi, in 1763 b.c.e. His Code of Laws, one of the first codes of law in world history, contained 282 rules including the principles of "an eye for an eye" and "let the buyer beware." The Code of Laws stated: "If a builder build a house for some one, and does not construct it properly, and the house which he built fall in and kill its owner, then that builder shall be put to death."

Many of the building codes used initially in North America were imported from Europe by the early settlers. In 1630, the City of Boston building code stated: "No man shall build his chimney with wood nor cover his roof with thatch." In 1865, the City of New Orleans adopted an ordinance requiring the inspection of buildings for public use. In 1905 the National Board of Fire Underwriters published the first national building code in the United States, the Recommended National Building Code.

Some notable evolutionary processes occurred over the past during the twentieth century. While local government has generally retained the authority to enforce building construction regulations, the development of the codes and standards they adopt has shifted away from "home grown" criteria of various state and local agencies towards voluntary sector activities. In 1927 the Pacific Coast Building Officials (a precursor to the International Conference of Building Officials) conference published the Uniform Building Code. Then, in 1945, the Southern Building Code Congress International published the Standard Building Code.

Federal Legislation Scope Date Enacted
Energy Conservation and Production ActDevelop performance standards for all new buildings8/14/76
New Buildings ActHUD shall promulgate, implement and enforce energy performance standards5/4/77
Department of Energy Organization ActTransfer authority from HUD to DOE8/4/77
Housing and Community Development Act of 1980DOE shall promulgate interim standards that apply only to Federal buildings10/8/80
Omnibus Budget Reconciliation ActStandards to be developed through private sector.8/13/81
Cranston-Gonzales National Affordable Housing ActEnergy efficiency standards for public housing11/28/90

Groups such as the American Society of Mechanical Engineers (ASME), National Fire Protection Association (NFPA), American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) and Underwriters Laboratories (UL) develop codes and standards for use by industry members. Model codes organizations including Building Officials and Code Administrators International (BOCA), International Conference of Building Officials (ICBO), and Southern Building Code Congress International (SBCCI) are code official organizations that develop model codes specific to their region of the country.


Energy codes and standards stem from policy directives in the early 1970s that were hastened by the Arab oil embargo. The Secretary of the Department of Housing and Urban Development was directed in 1971 to reduce maximum permissible energy loss by about one-third for a typical home and to revise the insulation standards for apartments. The resulting thermal envelope criteria in HUD's Minimum Property Standards became the first energy code.

The Arab oil embargo and ensuing "energy crisis" in late 1973 began to change the scope of building construction regulations. The public became quickly aware of the true cost of energy as gasoline prices skyrocketed. The oil embargo created a ripple effect that demanded a larger public policy role to reduce wasteful energy use.

Table 1 describes the ensuing legislation that was promulgated to promote energy efficient construction as a result of the Arab oil embargo.

Development of standards, codes, and other regulations to address energy in buildings began in earnest in the early 1970s. The Omnibus Budget Reconciliation Act prohibited the government from promulgating regulations that would apply to non-public construction. This left the task of energy codes and standards development up to two key processes. They are the model code processes set up by the building regulation community and the consensus processes set up by the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) and their co-sponsor, the Illuminating Engineering Society of North America (IESNA).

ASHRAE Consensus Process

Some states recognized the need and the role that they could play if energy criteria were added to their building codes. Through the National Conference of States on Building Codes and Standards (NCSBCS) a request was made by the states for the National Bureau of Standards (NBS) to develop some criteria that could be used to address energy issues through building codes. The NBS released suggested energy

Title Scope Description
ASHRAE/IES Standard 90A-1980All BuildingsUpdated Sections 1 through 9 of ASHRAE/IES Standard 90-1975 with more stringent provisions.
ASHRAE/IES Standard 90.1-1989Commercial and High Rise ResidentialUpdated entire commercial and high-rise residential standard with more stringent provisions.
ASHRAE Standard 90.2-1993Low Rise ResidentialUpdated low-rise residential standard with more stringent provisions.
ASHRAE Energy Code for Commercial and High Rise Residential BuildingsCommercial and High Rise ResidentialStandard 90.1-1989 in mandatory language for use by model code organizations.
ASHRAE/IESNA Standard 90.1-1999Commercial and High RiseUpdated entire commercial and high-rise residential standard with more stringent provisions

requirements for new building designs in early 1974. Since the NBS criteria had not received widespread input from and agreement by the building community the states looked to a voluntary sector standards development organization to develop a standard for building energy design. Using the NBS criteria as a starting point the ASHRAE established a Standard 90 project and committee and began the process of writing a standard in cooperation with the IESNA. Released in August of 1975, ASHRAE/IES Standard 90-75 addressed energy conservation in new building design.

The DOE sponsored two major projects with ASHRAE as a result of the Omnibus Reconciliation Act; Special Project 41 and Special Project 53. These projects led to a series of changes and has continued to be amended from time to time. Table 2 outlines the evolution of the ASHRAE/IES Standard through 1999.

Model Codes Development Process

Because the ASHRAE/IES standard contained both mandatory requirements and recommendations, it was difficult to adopt and implement as a uniform building code. Such codes must clearly state minimum requirements that can be uniformly interpreted and applied. For this reason it was determined that a model code was needed that contained only the mandatory requirements of Standard 90-75 and placed them in enforceable code language that would fit within a building code. Working with NCSBCS the three U.S. model code organizations (Building Officials and Code Administrators, International Conference of Building Officials, and Southern Building Code Congress) developed and released a model energy code for new buildings in late 1997: Model Conservation Energy Code (MCEC) 1977. Table 3 shows the evolution of the model codes from the MCEC to the International Energy Conservation Code (IECC).


In 1975, the Energy Conservation and Production Act tied the availability of federal funds to states for their energy conservation efforts to the adoption by states of an energy code for new building construction. Beginning in the mid-1970s states began to adopt energy codes in earnest. This was accomplished in three ways:

  1. Through individual state legislation, wherein the legislature adopted by reference a particular energy code or wrote the energy code requirements directly in the legislation.
Title Scope Description
Model Energy Code (MEC) 1983All BuildingsTechnically equivalent to ASHRAE/IES Standard 90A-1980
MEC 1986All BuildingsLow-rise residential thermal envelope provisions updated to improve stringency.
MEC 1988All BuildingsMinor upgrades.
MEC 1992All BuildingsLow-rise residential thermal envelope provisions updated to improve stringency.
MEC 1993All BuildingsReference to ASHRAE Energy Code incorporated into Chapter 6.
MEC 1995All BuildingsWindow provisions added to reference National Fenestration Rating Council.
International Energy Conservation Code 1998All BuildingsSimplified commercial provisions added as Chapter 7 and low-rise residential Solar Heat Gain Coefficient requirement.
  1. To convey the authority to adopt an energy code to a state regulatory agency such as the state energy office or state office with authority for a state building code.
  2. Take no action; leaving the decision up to local government.

Ultimately, the responsibility for properly implementing these legislative actions fell upon the local governments of counties and incorporated cities, towns, boroughs, and so on. In total there are over 2,000 counties in the United States and over 40,000 independent units of local government that have some ability to adopt, implement, and enforce energy codes.

Since 1975 numerous states have adopted energy codes through legislative or regulatory mechanisms. They range from those that apply to all new buildings to those that only apply to state-owned buildings, non-residential buildings, or only buildings in localities that have adopted a building code. Where the state has taken no action or only partial action on a selected building type, such as state-owned buildings, then local government is free to take action if it so chooses. In some cases state and local government are prohibited or preempted from taking any action.

Other notable adopters of energy codes are the U.S. Department of Housing and Urban Development, Department of Defense, and public utilities.

Once adopted there are many ways to implement and enforce energy codes. Where a state or local building code exists, there is already an adopted code and enforcement mechanism in place to ensure compliance with the energy code. Where no such building code infrastructure exists, then implementation in the absence of such support must rely on the following mechanisms:

  • Builder certification as a condition for utility connection
  • Warranty with penalties if non-compliance is verified
  • Contractor licensing tied to code compliance
  • Energy rating schemes that pull the market
  • Professional architect and engineer certification
  • Third party certification and inspection

Over time more states have secured authority to adopt and implement building codes and over time those codes have tended to be more uniform. Current activities are likely to keep the focus on national uniformity in the absence of Federal preemptive authority.

MEC Version or State Code that's Equivalent States Adopted
98 IECC, For state-owned and stated-funded buildings1 State (NE)
Exceeds 95 MEC, Statewide adoption/equivalence4 States (CA, FL, OR, MN)
Exceeds 95 MEC, Partial adoption or equivalence (i.e. only state funded bldgs, dependent on local jurisdiction, etc.)2 States (AK, WA1)
95 MEC, Mandatory statewide adoption/equivalence13 States (CT, GA, MD, MA, NC, NH, RI, SC, OH, VA, VT, UT, WI)
95 MEC, Partial adoption/equivalence3 States (OK, LA2, HI2)
93 MEC, Mandatory statewide adoption/equivalence1 State (DE)
93 MEC, Partial adoption/equivalence5 States (TX3, ND, MT, AL, KS)
92 MEC, Mandatory statewide adoption/equivalence7 States (AR, IN, IA, KY, NM, TN, NY)
1 Code exceeds 95 MEC for electrically heated buildings, but is less stringent for non-electrically heated buildings.
2 LA and HI have 95 MEC adopted for multi-family low rise only.
3 TX is listed twice because 93 MEC is mandatory only for state funded low-rise bldgs. Local jurisdictions are adopting 92, 93, 95 MEC on their own.


The Energy Policy Act of 1992 (the Act) was a major policy action to promote the improved use of the nation's energy resources. The Act includes both improving the supply of energy resources and promoting the efficient use of those resources. One aspect of the Act focuses on improving the efficiency of new buildings through upgrading and adoption of energy efficiency codes and standards. The Act, combined with technical and financial support, provides states with an unprecedented level of federal support to improve the efficiency of new buildings.

State and locally adopted energy codes are supported by the Federal government in three ways:

  • Federal law requires that States act to review and upgrade their codes.
  • Technical support is provided by DOE in the form of tools, training programs, code user support through a toll-free number, and analysis directed by the states.
  • DOE provides financial support in the form of over $4 million in special projects funding annually.

Since the adoption of the Act in 1992, state-of-the-art energy codes have been extended to cover an additional 39 percent of residential construction and 26 percent of commercial construction. Two-thirds of new U.S. residential construction (1 million homes annually) fall under federal, state, and local energy codes that meet or exceed the 1995 version of the Model Energy Code (MEC). An additional 975 million square feet of commercial construction falls under codes that meet or exceed ASHRAE/IES Standard 90.1-1989. Table 4 shows the status of state residential code adoption as of August 1999.

On December 9, 1994, the International Code Council (ICC) was established as a nonprofit organization dedicated to developing a single set of comprehensive and coordinated national codes. The ICC founders—the Building Officials and Code Administrators (BOCA), the International Conference of Building (ICBO), and the Southern Building Code Congress International (SBCCI)—created the ICC in response to technical disparities among the three sets of model codes now in use in the United States.

Since 1972, the Council of American Building Officials (CABO) has served as the umbrella organization for BOCA, ICBO, and SBCCI. In November 1997, it was agreed to incorporate. CABO into the ICC. Responsibility for developing and maintaining the Model Energy Code (MEC) was transferred from CABO to the ICC in order to provide proper interface with the International Codes.

The first version of the International Energy Conservation Code (IECC) was published in 1998.


As with any market, the new construction market has a wide range of efficiencies within its participants. In theory, energy codes can shift the average efficiency of the market by eliminating the option of building to an efficiency level lower than that mandated by the code. This effect can produce significant savings even when the code minimum is set at the market "average" efficiency level.

Evidence from numerous code evaluations suggests that energy codes have transformed markets in three ways:

  1. In areas where codes are well enforced, the stock of poor performing new buildings has been reduced to a minimum, and
  2. In areas where utility incentive programs were successful, the overall efficiency of a typical building exceeds code.
  3. Codes have brought more efficiency technologies into widespread use in the market (e.g., vinyl window frames, T-8 fluorescent lamps).

The focus of codes and standards will shift from specifying the installation of prescriptive measures to the actual performance of the final building. This shift is consistent with an overall emphasis on objective or performance-based codes within the building code community. The next generation of energy codes will

  • Incorporate new technologies and practices into the standard that replace less efficient technologies and practices,
  • Assure proper performance of measures once specified and installed thereby assuring that energy and environmental benefits to energy codes are realized by building owners and occupants, and
  • Improve enforcement through partnerships and support of innovative enforcement practices by local governments.

Jeffrey A. Johnson David Conover

See also: Building Design, Commercial; Building Design, Residential.


American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). (1999). ASHRAE/IESNA Standard 90.1-1999 Energy Standard for Building Except Low Rise Residential Buildings. Washington, DC: Author.

Building Codes Assistance Project.BCAP—Building Codes Assistance Project. Washington, DC: Author. <>.

International Energy Conservation Code 2000. (2000). Falls Church, VA: International Code Council.

U.S. Department of Energy. (July 20, 2000). Building Standards & Guidelines Program (BSGP). Washington, DC: Author. <>.