The International Energy Conservation Code (IECC) is an international standard developed through a consensus-based public process every three years. Each new published version achieves a higher efficiency in the built environment. The most-recent version of the IECC for 2021 is expected to have a 10% savings over the 2018 IECC. The IECC is known for addressing the energy-efficient design of buildings and innovation of the codes while protecting the health and safety of the public. 

Development and adoption of the energy codes can be instrumental in achieving Nevada’s climate goals. The IECC is developed on a triennial schedule through a fair, robust process that includes building officials, national builders, state government officials, and others that are responsible for the adoption of the codes. During the 2021 IECC development and adoption process, the Nevada Governor’s Office of Energy (GOE) participated along with the Nevada Division of Environmental Protection (NDEP) in the public comment hearings in Las Vegas and the online vote. Both processes requiring voting members to qualify under the International Code Council Policies as defined in Council Policy 28.

Pursuant to NRS 701, the GOE must adopt the most recently published version of the IECC or provide reason against the adoption of the standard. Upon each publication and adoption, the GOE is required to submit a statement to the U.S. Department of Energy (DOE) identifying the analysis conducted and whether the version was adopted in the state. In 2017, the GOE adopted regulations that authorized the automatic adoption of the most-recent IECC on a triennial basis. 

Energy codes are projected to save U.S. homes and businesses $126 billion between 2012 and 2040. These numbers were calculated with the assumption that new, updated codes would continue to be adopted

In order to effectuate change in the built environment, the adoption of the IECC as it is published allows Nevada to support robust, strong energy codes that continue to improve and provide affordable, comfortable, safe, and innovative residences and businesses to all Nevadans. To increase the efficiency of the built environment, states have also adopted above-code programs, which provide incentives for local jurisdictions to adopt the current code with amendments to increase the efficiency by a certain percentage.

Currently in Nevada, the GOE adopts the IECC for subsequent incorporation by local governments. However, this is done on a cycle that is incongruent with the adoption at the state level. Some jurisdictions have not adopted an energy code at all, while others have adopted the 2018 IECC as shown in Figure 1.

Figure 1. IECC Code Adoption in Nevada. (Data from IECC)

Figure 1. IECC Code Adoption in Nevada. (Data from IECC)


The DOE is required by federal statute (42 U.S.C. 6833) to determine if the newly published version of the standard would achieve greater efficiency in buildings when compared to the previous version. Quantifying greenhouse gas (GHG) reductions through the adoption and implementation of the 2021 IECC has not been done. However, previous determinations have concluded that a 5.1% savings in the 2018 IECC over the 2015 IECC was achieved. Based on the EPA’s AVERT tool, this avoided 102,412 lbs of SO2, 107,840 lbs of NOx and 137,570 tons of CO2 (Table 1).

Table 1. Avoided emissions and electricity generation displaced by EE/RE policies and programs as calculated using the EPA AVERT tool.

Annual State Emission Changes (Northwest Region) Due to Changes in Nevada

STATESO2 (lbs)NOx (lbs)CO2 (tons)PM 2.5 (lbs)

Annual Regional Displacements (Northwest Region) Due to Changes in Nevada

OriginalPost-Energy Efficiency/Renewable EnergyEnergy Efficiency/Renewable Energy Impacts
Generation (MWh)132,302,160131,218,660-1,083,500
Total emissions of fossil electricity generating units
SO2 (lbs)95,417,94094,680,110-737,830
NOx (lbs)144,287,390143,152,860-1,134,530
CO2 (tons)104,233,730103,425,650-808,070
PM 2.5 (lbs)10,942,01010,850,380-91,630

For this policy, estimates in the changes in net electricity consumption over time as a result of policy adoption consistent with the IECC would be necessary to get a clear picture of what GHG emissions reductions could be achieved and on what time horizon. 

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Statewide IECC adoption would ensure efficiency standards and lower energy bills for all Nevadans, including those in low- to moderate-income (LMI) communities. 

Adopting the IECC is expected to have a positive impact on LMI communities, communities of color, Indigenous peoples, and other vulnerable populations. Efficiency requirements found in the IECC will lower utility energy bills, thus reducing the energy cost burden on each family. Energy burden is defined as the percentage of a household’s income that goes toward energy bills such as electricity and natural gas. Studies show that low-income households have energy burdens that are three times higher than other households. Reducing energy costs would free up additional funds for households to put toward other uses.

Adopting the IECC may also have the additional benefit of creating healthier indoor environments. By requiring new construction and renovations to include efficient insulation, weatherization, and HVAC systems, the Code may lead to improved air quality, and in turn, fewer health issues.

Renters may benefit the most from these codes, as that group generally does not make upgrades or repairs to their rented units themselves. This group is therefore dependent on the existing quality of new construction, or on the building owner to perform renovations in a certain manner. Aging apartment buildings are likely to require renovation and repairs that would trigger IECC requirements. In addition, new-build affordable housing is often in the form of apartment buildings. However, this is also expected to benefit homebuyers acquiring newly built housing. This might include affordable single-family housing, and housing constructed using loans from United States Department of Agriculture (USDA) Rural Development or similar.

Establishing a reasonable timeline for the implementation of the IECC will ensure that local jurisdictions adopt it efficiently. Creating incentives may ensure that the code is adopted quickly. The sooner the IECC is implemented, the more people will benefit.

A 2015 study determined that adopting that year’s IECC version would save households over $500 per year compared to the 2006 version. By continuing to implement the most-recent version of the Code, local jurisdictions could ensure even greater household savings in the future.

Implementing the IECC is not expected to have negative impacts to vulnerable populations. Since the Code pertains to new construction and alteration (renovations and repairs), it will have no effect on households who live in existing buildings that are not undergoing alteration. 

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Financial implications of IECC code adoption varies greatly depending on the scope of authority defined by any authorizing language.

States are classified on a spectrum as either a ‘Home Rule’ state or a ‘Dillon Rule’ state. In a Home Rule state, the authority having jurisdiction (AHJ) is authorized to adopt codes and standards—without the state or in contradiction to the state. However, in Dillon Rule states, the state is the AHJ. Nevada is a Dillon Rule state with limited home rule for some local government functions, and building code adoption is currently a home rule arrangement.

For example, in Colorado, a Home Rule state, legislation was passed in 2019 that requires local jurisdictions to adopt and enforce one of the three most-recent versions of the IECC upon updating a local building code. The fiscal impact to the state is minimal, however there is no information on the impacts to the local governments or AHJs.

In Utah, HB 218 (2019) adopted the 2015 IECC for residential buildings and 2018 version for commercial buildings. The fiscal note for HB 218 showed $0 expected cost impact to state government, local government, businesses, and individuals. There are two staff members listed as building code specialists, but the budget is unclear (DAS).

In Montana, there were further expenses to the state based on the adopted code 2012 IECC and the stretch code created through SB 49 (2009) for new State-owned and -leased buildings under the state’s High-Performance Building Standards. These buildings must exceed the IECC most recently adopted by Montana’s Department of Labor & Industry (DLI) by 20% to the extent it is cost effective. The fiscal note for SB 49 showed expenditure of $62,306. This is for 1 full-time equivalent (FTE) to continue work on the high-performance building standard, as well as $2,200 in initial-year operating expenses to implement. The Energy Bureau within Montana Dept of Environmental Quality has two branches: Energy Efficiency and Compliance Assistance (EECA), and Energy Planning and Renewables. EECA shows energy code staffing of at least 1 and up to 7 (possibly 3 energy engineers, 1 small business ombudsmen, 2 energy resource professionals).

The fiscal impact falls largely to the AHJs that have the responsibility of adopting the codes. The AHJs must adopt the family of international construction codes, including the IECC, each adoption cycle due to their nature of working in conjunction with each other. They must also implement and enforce the code in their jurisdictions, which requires staff and funding.

While it is difficult to assess the impact on Nevada, implementation of energy codes does require resources for ongoing administration. Further analysis is required and AHJs should be included in that analysis to identify specific resource requirements.

“Internationally, code officials recognize the need for a modern, up-to-date energy conservation code addressing the design of energy-efficient building envelopes and installation of energy-efficient mechanical, lighting, and power systems through requirements emphasizing performance. The International Energy Conservation Code is designed to meet these needs through model code regulations that will result in the optimal utilization of fossil fuel and non-depletable resources in all communities, large and small.

This code contains separate provisions for commercial buildings and for low-rise residential buildings (three stories or less in height above grade). Each set of provisions, IECC—Commercial Provisions and IECC—Residential Provisions, is separately applied to buildings within their respective scopes. Each set of provisions is to be treated separately. Each contains a Scope and Administration chapter, a Definitions chapter, a General Requirements chapter, a chapter containing energy efficiency requirements and existing building provisions applicable to buildings within its scope.

This comprehensive energy conservation code establishes minimum regulations for energy-efficient buildings using prescriptive and performance-related provisions. It is founded on broad-based principles that make possible the use of new materials and new energy-efficient designs. This IECC is fully compatible with the Family of International Codes.”

— International Code Council

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There may be adequate legal authority currently to implement this policy, but, it may be prudent for the Nevada Legislature to amend NRS 701.220 to provide explicit direction.

The GOE director has the authority through NRS 701.220 to adopt regulations for the conservation of energy in buildings, including manufactured homes. The regulations “must include” 1) adoption of the most-recent version of the IECC and 2) any amendments to the IECC that will not materially lessen the effective energy-savings requirements and are deemed necessary to support effective compliance and enforcement (NRS 701.220(1)). It may be prudent for the legislature to amend NRS 701.220(4) to explicitly add a reasonable deadline (e.g., 18 months after the director adopts the most-recent version of the IECC) for local governments to adopt these standards.

In addition, legislation could be included allowing the director to adopt other codes and standards, such as the International Green Construction Code (IgCC) or the National Green Building Standard (ICC 700-2020).

Under NRS 701.220(4), the governing body of a local government that is authorized to adopt and enforce a building code “shall incorporate” the director’s standards into its building code. However, it is possible that a county government could assert that its building code is a “matter of local concern,” as defined in NRS 244.143, and refuse to adopt the director’s standards, such as a stretch code. We believe this argument is likely to fail because “matters of local concern” excludes state interests that require statewide uniformity of regulation (NRS 244.143(1)(c)(1)). The legislature made it clear that Nevada has an interest in uniform, state-wide, minimum standards for conservation of energy and energy efficiency in buildings, which must be incorporated into local building codes (NRS 701.220(4)). In addition, NRS 244.143 explicitly states, “If there is a . . . statutory provision requiring a board of county commissioners to exercise a power . . . in a specific manner, the board may exercise the power only in that specific manner.” Here, NRS 701.220(4) explicitly provides that local governments “shall incorporate” the director’s standards into their building codes. Still, additional analysis of Nevada’s home rule statute is recommended prior to adoption of this policy.

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