State and Local Policy Database

Residential Codes

Mandatory residential building codes require a minimum level of energy efficiency for new residential buildings. The Department of Energy estimates that between 1992 and 2012, residential codes resulted in cumulative energy savings of 1.8 quads. They project that an additional 21.2 quads will be saved through 2040 due to residential building energy codes.

The Alabama Energy and Residential Code (AERC) Board recently adopted the 2015 Alabama Residential Energy Code. While the residential code is based on the 2015 IECC, state-specific amendments weaken it significantly, making it more efficient than the 2009 IECC but not equivalent to the 2015 IECC. The updated residential code took effect October 1, 2016. Local jurisdictions may adopt more stringent codes, and several have adopted the 2015 IECC without the state-adopted amendments.

Last Updated: June 2018

Alaska does not have a mandatory statewide code for new residential construction. However, since July 2013, residential construction projects financed by the Alaska Housing Finance Corporation have been required to meet the state-developed Building Energy Efficiency Standards (BEES), which is based on the 2012 IECC with state-specific amendments. Since the corporation finances approximately 20% of the market share, the majority of homes in Alaska are built to this standard. In addition, Alaska's Cold Climate Housing Research Center (CCHRC) found that about 68% of new residential construction adheres to BEES.

Last Updated: August 2017

Arizona is a home-rule state, meaning that codes are adopted and enforced on a local rather than state level. However, the Southwest Energy Efficiency Project has found that the majority of new construction activity occurs in jurisdictions who have adopted the 2012 IECC or 2015 IECC.

Last Updated: October 2018

The Arkansas Energy Code for New Building Construction is mandatory state-wide for both residential and commercial buildings. The residential energy code is based on the 2009 IECC with amendments. This code became effective on January 1, 2015.  

Last Updated: August 2017

The 2016 Building Energy Efficiency Standards were adopted in June 2015, effective January 1, 2017 In June 2017 the California Energy Commission certified to U.S. DOE that the 2016 Standards exceed IECC 2015 by 29% on average for the residential building types analyzed (see Energy Commission Residential Energy Efficiency Comparison)..  The 2016 Reach Standards, published in the California Green Building Standards (CALGreen), were adopted in October 2015, effective January 1, 2017, and establish standards for Energy Design Ratings that are 15% (Tier I) and 30% (Tier II) beyond the mandatory standards, as well as a Zero Net Energy Design designation, which local governments consider for adoption as local ordinances.

In May 2018, the CEC adopted the 2019 Building Energy Efficiency Standards, which take effect on Jan. 1, 2020, and are the first in the nation to require solar. The codes focus on four key areas: smart residential photovoltaic systems, updated thermal envelope standards, residential and nonresidential ventilation requirements, and nonresidential lighting requirements. 

Last Updated: October 2018

The 2003 IECC is a mandatory minimum for jurisdictions that have adopted a code previously. Jurisdictions that have not adopted or enforced codes are exempt from the 2003 IECC requirement, although the 2012 IECC is mandatory for all factory-built and multi-family structures – commercial and residential – in areas that do not adopt or enforce buildings codes. The State of Colorado Division of Fire Prevention and Control regulates the construction of health care and school facilities, and the 2015 IECC is mandatory for these specific construction types as well. Otherwise, Colorado has no rule-making authority to require jurisdictions to adopt any code. 67% of construction activity occurs in communities that have adopted the 2012/2015 IECC or greater. In addition, the average HERS Index Rating for single family residential homes in Colorado dropped from 59 to 57 over the last year, showing a 2% energy reduction.

Last Updated: July 2018

Following a review that began in January 2017 by the state's Codes and Standards Committee and Department of Administrative Services, state regulators voted in July 2018 to move forward with adoption of the 2018 Connecticut State Building and Fire Safety Codes, which include the 2015 IECC  for residential and commercial construction. The Connecticut Department of Administrative Service has announced its intent to adopt the 2015 IECC effective October 1, 2018.

Details regarding the state's code adoption process and schedule can be found on its Code Adoption Webpage. In addition, Connecticut Law now provides the State Building Inspector and Code Committee a process to adopt and implement the latest IECC during the same year.  

Last Updated: September 2018

Residential construction in Delaware must comply with a weakened version of the 2012 IECC. The state is currently reviewing the 2015 and 2018 IECC. Residential and commercial codes are reviewed triennially by the Delaware Energy Office within the Department of Natural Resources and Environmental Control.

Last Updated: July 2018

Washington DC's energy codes are mandatory across the District. For residential buildings, builders must comply with the 2013 DC Energy Conservation code, which is roughly equivalent to the 2012 IECC.  The District also has a Green Construction Code that enhances energy efficiency requirements in addition to the energy code.  It applies to all commercial construction projects 10,000 square feet and larger and all residential projects that are 10,000 square feet and larger and four stories or higher.

Last Updated: July 2018

Effective December 31, 2017, Florida law requires that residential buildings comply with the 6th Edition (2017) Florida Building Code, Energy Conservation. The 6th Edition (2017) Florida Building Code, Energy Conservation consists of the foundation code 2015 IECC and amendments. (See https://codes.iccsafe.org/public/collections/FL). The Florida Building Commission certified in letters to the U.S. Department of Energy that the new code meets or exceeds 2015 IECC standards. Compliance with the code is mandatory for all new construction including alteration to existing buildings.

Last Updated: June 2018

On January 1, 2011, the 2011 Georgia State Minimum Standard Energy Code became effective statewide as approved by the Georgia Department of Community Affairs on November 3, 2010. The state code is based on the 2009 IECC with 2011 Georgia Amendments and is mandatory statewide.

Last Updated: July 2018

In July 2015, the Hawaii State Building Code Council adopted the 2015 IECC with state-specific amendments. The new codes took effect on July 1, 2015. However, until each county adopts the 2015 IECC, the counties of Hawaii, Maui, and Honolulu enforce the 2006 IECC; Kauai, the 2009 IECC. 

Last Updated: October 2018

The State of Idaho adopted the 2012 IRC with amendments that place it at 2009 standards. Idaho has adopted 2012 IECC residential provisions with amendments to 2009 standards for residential code, which took effect as of January 1, 2018. There are a few jurisdictions that adopted the 2015 suite of codes in 2017, including: Boise, Rathdrum, Idaho Falls, Ammon, Sun Valley, Rupert, Kuna, Sandpoint, Bannock County, Blaine County, Minidoka County, and Bear Lake County. Heyburn adopted the 2015 IRC codes only.

Last Updated: June 2018

By law Illinois is required to adopt the latest IECC, although the Capital Development Board may recommend amendments. Current code, effective January 2016, requires residential construction to meet 2015 IECC standards with state-specific amendments. 

Last Updated: July 2017

The Indiana Energy Conservation Code is state-developed and mandatory statewide. For residential buildings, the 2011 amendments update the 2005 Indiana Residential Code to reference Chapter 11 of the 2009 IRC, with the amendments meeting the stringency of Chapter 4 of the 2009 IECC, effective as of April 5, 2012.

Last Updated: August 2017

The Iowa State Energy code is mandatory statewide for residential buildings, although jurisdictions are free to adopt stricter codes. As of March 2014, residential buildings must comply with the 2012 IECC, with state-specific amendments. 

Last Updated: July 2018

Kansas is a home-rule state and thus has no statewide residential building code, though realtors and homebuilders are required to fill out an energy-efficiency disclosure form and provide it to potential buyers. Many jurisdictions have adopted the 2009 or 2012 IECC. Based on information obtained in a 2013 survey of local jurisdictions and 2011 U.S. Census permit data, it is estimated the almost 60% of residential construction in Kansas is covered by the 2009 and 2012 iterations of the IECC. 

Last Updated: August 2017

As of October 1, 2014, the 2013 Kentucky Residential Code (KRC) mandates residential buildings must comply with the 2009 IECC or IRC with state amendments.

Last Updated: July 2018

Residential buildings must meet the 2009 IRC with reference to the 2009 IECC. Multifamily residential construction three stories or less must comply with the 2012 IRC and the energy provisions of the 2009 IECC. Multifamily residential construction over three stories must comply with ASHRAE 90.1-2007.

Last Updated: July 2018

The Maine Uniform Building and Energy Code (MUBEC) was established legislatively in April 2008 through P.L. 699, setting the 2009 IECC and ASHRAE 90.1-2007 as the mandatory for residential buildings statewide, effective June 1, 2010 with a six-month transition period. In 2011, P.L. 408 changed mandatory enforcement requirements for the Maine Uniform Building and Energy Code (MUBEC) to municipalities with populations over 4,000 starting December 1, 2010 for municipalities that had existing building codes and December 1, 2012 for municipalities that did not have existing building codes. For municipalities with a population less than 4,000 enforcement of the statewide code is voluntary. This change means that 89 of Maine’s 533 municipalities (based on 2010 census data) are required to provide enforcement of energy codes, representing 60% of the state’s residential population. The Technical Codes and Standards Board is currently working on the adoption of the 2015 IRC, IEBC, and IECC.

Last Updated: July 2018

Effective January 1, 2015, the 2015 Maryland Building Performance Standards are mandatory statewide and reference the 2015 ICC Codes, including the 2015 IECC, for all new and renovated residential buildings. § 12-503 of the Maryland Code requires the Department of Housing and Community Development to adopt the most recent version of the IECC within eighteen (18) months after it is issued and may adopt energy conservation requirements that are more stringent than the codes, but may not adopt energy conservation requirements that are less stringent. Each locality in the state must adopt and begin enforcement of the code within 12 months of state adoption.

Last Updated: September 2018

The Board of Building Regulations and Standards (BBRS) has adopted the 9th edition of the MA state building code. The updated code went into effect in August 2016, and the energy chapters reference the IECC 2015 and ASHRAE 90.1-2013, with strengthening amendments. The Board also updated the state stretch energy code to exceed the baseline state code by approximately 10% for new construction. The stretch code is now adopted in approximately two thirds of the state population.

Last Updated: July 2018

The 2015 Michigan Residential Code went into effect in February 2016 and is based on the 2015 IECC with Michigan-specific weakening amendments.

Last Updated: August 2017

Minnesota's residential building code is mandatory statewide. The IECC 2012 was adopted in August 2014 and went into effect February 2015.

Last Updated: July 2018

Mississippi's residential code is voluntary and is based on ASHRAE 90 – 1975 and the prior 92 MEC. Based on a June 2011 Energy Codes Economic Analysis conducted by BCAP and Southface, as well as additional data collected by MDA, approximately 60% (1.75 million out of a total 2.9 million residents) of the State’s population reside in cities or counties with building codes equivalent to 2003 IBC or higher, and the average code standard for these local jurisdictions is 2006 ICC. Jurisdictions can adopt more stringent codes, and several localities have done so for the residential code: Gulfport, Biloxi, Horn Lake, Ridgeland, Jackson, Greenville, Oliva Branch, Pascagoula, and Moss Point.

Last Updated: August 2017

Missouri is a home-rule state and thus has no mandatory state-wide codes. State-owned residential buildings must comply with latest edition of the MEC or the ASHRAE 90.2-1993 (single-family and multifamily buildings). Missouri maintains a database of building code adoptions in local jurisdictions. Approximately 50% of the state’s population is covered by the 2009, 2012, or 2015 IECC or equivalent codes.

Last Updated: June 2018

Montana's residential building code, codified in ARM Title 24, Chapter 301.160, is mandatory statewide. Montana's residential code requires compliance with the 2012 IECC, with amendments.

Last Updated: July 2018

Nebraska is a home-rule state, but its residential energy code, referred to as the Nebraska Energy Code (NEC), is mandatory statewide. Residential buildings are required to comply with the 2009 IECC with administrative amendments. Local jurisdictions can adopt any code that is more stringent than the NEC, and two municipalities have adopted the 2012 IECC: Gretna and Fremont. Nonetheless, 100% of new homes fall under the 2009 IECC as the NEC is the minimum standard. The Energy Office has conducted a study on the impact of the 2015 IECC, and is awaiting the final report.

Last Updated: July 2018

On July 1, 2015, the 2012 IECC became mandatory for residential buildings. While the code is not being enforced statewide, a significant number of localities have adopted it. Local jurisdictions are not allowed to adopt less-efficient energy codes.

Last Updated: August 2018

Effective April 1, 2010, the New Hampshire State Building Code for residential buildings is based on the 2009 IECC, with state-specific amendments. The code is mandatory statewide. The NH Building Code Review Board is currently reviewing the 2015 IECC.

Although New Hampshire is not a home rule state, statutes allow municipalities to adopt amendments and codes provided they exceed the State Building Code. The town of Durham has adopted the 2015 IECC energy code (strengthened).

Last Updated: August 2017

The 2015 New Jersey Uniform Construction Code for residential and commercial buildings is mandatory statewide as of September 2015. Residential construction must comply with an amended version of the 2015 IECC. The code includes a modification to Section R402.4.1 (Building thermal envelope) of the IECC/2015 which allows for either a visual inspection with checklist or [blower door] testing for compliance with the air barrier and insulation aspects of the building thermal envelope requirements. If testing is used, the 2015 criteria of 3 air changes per hour is the criteria to meet. 

For existing buildings, the Rehabilitation subcode (NJAC 5:23-6) applies certain energy conservation provisions of the new codes based on the scope of the project.

Last Updated: July 2018

The 2009 New Mexico Energy Conservation Code (NMECC) is based on the 2009 IECC with state-specific amendments for residential building codes. All areas of the state are covered by local building jurisdictions and must meet or exceed the state minimum code. Because localities are permitted to adopt stretch codes, the City of Santa Fe and Town of Taos have adopted more stringent building codes. Builders can also use the NM 2009 Energy Conservation Code Residential Applications Manual to comply when building a passive solar or high mass home. The New Mexico Home Builders association is considering a request to update the residential code to IECC 2015.

Last Updated: August 2017

On March 9, 2016, the Fire Prevention and Building Code Council voted to adopt major updates to the New York State Energy Conservation Construction Code, incorporating the 2015 International Energy Conservation Code, ASHRAE 90.1-2013 and 2016 Energy Code Supplement. Effective October 2016, residential buildings must comply with the 2015 IECC. 

The State Fire Prevention and Building Code Council is empowered to adopt higher or more restrictive standards upon the recommendation of local governments. New York State began developing a stretch energy code with contributions from an advisory group and technical working groups represented by state and local government, utilities, design professionals, building trades and advocacy groups.  Named NYStretch-Energy, this state stretch code will be marketed statewide for optional local adoption in the second quarter of 2017.

Last Updated: July 2018

The 2012 North Carolina Energy Conservation Code (NCECC) is mandatory statewide for residential buildings. The residential code is based on the 2009 IECC with substantial strengthening amendments.

Last Updated: July 2018

North Dakota is a home rule state and has no statewide mandatory energy codes. The state recently adopted an amended version of the 2015 IECC as its voluntary residential code. Approximately 83% of the state’s population lives in a jurisdiction that has adopted the ND State Building Code which includes the 2009 IECC.

Last Updated: August 2017

Ohio's residential energy code is mandatory statewide and requires compliance with the 2009 IECC. Residential home builders are also allowed to meet the requirements of sections 1101-1103 of Chapter 11 of the Residential Code of Ohio (based on Chapter 11 of the 2009 IRC) or by meeting the state code's new Prescriptive Energy Requirements (section 1104).

Last Updated: August 2017

Oklahoma has in place mandatory statewide building codes for residential and commercial buildings buildings. The Oklahoma Uniform Building Code Commission (OUBCC) reviews and recommends building codes for residential and commercial construction. Residential buildings must comply with the 2015 IRC, however, the energy chapter references the 2009 IRC.

Last Updated: July 2018

The 2014 Oregon Energy Efficiency Specialty Code is mandatory statewide. Its provisions are developed by the state and are not based on a model code. The state currently enforces the 2014 Oregon Residential Specialty Code (ORSC), which has been certified to US DOE as equivalent/more efficient to IECC 2015. Oregon has approved IECC 2015 as an alternative and is putting in place provisions for it to replace the current Reach Code. Reach Code compliance is mandatory for all new state-owned and occupied buildings and substantial remodels. Oregon adopted a new Residential Code in 2017 (2017 Oregon Residential Specialty Code, or 2017 ORSC), which became effective October 1, 2017, with a 90-day phase-in period. The 2017 ORSC is based on the 2015 IECC with Oregon amendments, which include mandatory alternative efficiency package pathways for envelope efficiency and equipment such as furnaces, water heaters, and heat pumps that exceed federal minimums.

Last Updated: June 2018

Pennsylvania's residential energy code is mandatory statewide. Residential buildings must comply with the 2009 IECC or 2009 IRC, Chapter 11. Residential buildings can also comply with Pennsylvania’s Alternative Residential Energy Provisions (2009). Municipalities can propose more stringent codes to the Department of Labor and Industry, the approving authority. All 2,562 jurisdictions have mandatory building energy codes for residential and commercial construction. The PA Uniform Construction Code Review and Advisory Counil recently recommended adoption of the 2015 I-Code (some with amendments) to the PA Labor and Industry Secretary. The Regulation will be effective October 1, 2018.

Last Updated: June 2018

On July 1, 2013, Rhode Island formally adopted the 2012 IECC for residential buildings, with state-specific amendments. The code went into effect on October 1, 2013 and is mandatory statewide. While Rhode Island is a home rule state, towns are not permitted to adopt a code that is different from the state's. The code contains several amendments that diverge from the ICC published version of the 2012 IECC. The residential code utilizes the 2009 IECC insulation tables, which is not as rigorous as the 2012 IECC.  Rhode Island requires performance testing but does not require that the air exchange rate meet code. While there is no current stretch code, as part of the Rhode Island’s Energy Efficiency Procurement Plan, a Building Codes & Standards Initiative has been approved by the RI Public Utilities Commission, and a stated feature is the development of a “stretch” code targeting “15% more energy than buildings constructed according to the prevailing path.” This effort is being pursued in conjunction with the RI Building Code Commission and the RI Builder’s Association.

Issued in December, 2015, Executive Order 15-17 directs the Office of Energy Resources to coordinate with the Energy Efficiency and Resource Management Council, National Grid, and the Green Building Advisory Committee to establish a voluntary aspirational or stretch building code based on the International Green Construction Code or equivalent by 2017. Rhode Island now has a voluntary stretch code for residential buildings.

Last Updated: June 2018

On January 1, 2013, the 2013 South Carolina Energy Standard became effective. The residential provisions reference the 2009 IECC. Local jurisdictions may adopt more stringent energy codes.

Last Updated: August 2017

South Dakota has no mandatory statewide energy codes for residential construction. Codes are adopted by jurisdiction voluntarily. As of July 2011, state law established the 2009 IECC as a voluntary residential standard, however most jurisdictions have adopted codes based on the 2015 IECC. Local jurisdictions also have authority to adopt various residential building and energy codes, including IRC and IECC.

Last Updated: October 2018

State building codes adoption and enforcement efforts fall under the purview of the State Fire Marshal’s Office within the Department of Commerce and Insurance (C&I). Any changes to building energy code must comply with the state’s rule-making procedures. On November 2, 2015, C&I conducted a rulemaking hearing to adopt the 2009 IECC for residential one and two family dwellings and townhouses. The permanent rules were filed with the Secretary of State on November 4, 2016 and went into effect on February 2, 2017. See http://share.tn.gov/sos/rules/0780/0780-02/0780-02-23.20170202.pdf and https://www.energycodes.gov/adoption/states/tennessee for additional information.

However, because Tennessee is a “home rule” State, significant variation exists in codes adoption and enforcement at the local level. Under Tennessee statute, all local jurisdictions must adopt a residential energy code that is within seven years of the most recently published energy code. However, all local jurisdictions may also opt out of adoption with a two-thirds majority vote of the local governing body. In addition, local jurisdictions cannot be required to adopt a local code that is more stringent than the one adopted by the State, but they may voluntarily choose to adopt an updated code version. If opting out, the vote must be completed after each local election cycle. To date, 86 jurisdictions have opted in to the state residential building code (apply the statewide building code to their jurisdiction and utilize the state’s building permit system and building inspectors), 80 jurisdictions have opted out (building codes are not recognized nor enforced), and 264 jurisdictions are exempt (building codes are adopted locally, meeting or exceeding the statewide standard; exempt jurisdictions hire their own inspectors and all paperwork is administered locally and audited on a 3 year cycle).

The State began implementation and enforcement of adopted energy codes for new building projects in July 2011. The State Fire Marshal’s Office requires a State building permit for new residential and certain commercial construction in areas of the State, except those where an exempt local government is enforcing a residential or commercial building code itself or where the local government has notified the Department it has opted out of the law. Building construction projects subject to code enforcement by the State Fire Marshal’s Office are required to obtain a State building code permit prior to commencing construction. The Department verifies contractors' licensure as part of the permitting process.

According to C&I, a number of local jurisdictions have adopted building energy codes that exceed versions adopted by the State. TDEC OEP is aware of at least 109 local jurisdictions that have already adopted the 2012 Residential IECC, and 11 that have adopted the 2015 IECC.

Last Updated: July 2018

Texas' building codes are mandatory for residential construction. The Texas Building Energy Performance Standards requires single family homes to comply with the 2015 IRC and all other residential buildings to comply with the 2015 IECC. For all buildings, jurisdictions can choose to adopt more stringent standards. More than 50 jurisdictions, representing approximately 5.3 million people, have adopted codes more stringent than the minimum state requirements. 

Last Updated: August 2017

Utah’s Uniform Building Code (UUBC) for residential building energy codes is mandatory statewide. Residential building construction must comply with an amended version of the 2015 IECC. While localities may adopt stretch codes, it is a difficult process to do so. Localities may only adopt stretch codes if approved through the state legislative process. Amendments may not be adopted at the local level. As a result, none have adopted stretch codes.

Last Updated: June 2018

Vermont’s residential building energy code is mandatory statewide. Effective March 1, 2015, the RBES references the 2015 IECC with Vermont-specific amendments. The state is required by statute to update its codes every three years. 

Act 89 of 2013 gives the Vermont Public Service Department the authority to develop stretch codes and municipalities have the option of adopting them. The state's Residential Stretch Energy Code went into effect December 1, 2015. Any projects encompassed by Residential Act 250 are required to adopt the Residential Stretch Code. Thise code has a higher level of thermal energy efficiency than the Base CodeBoth Residential Base and Stretch Energy Codes also allow renewable energy to be used to meet the target Home Energy Rating Scores for compliance. Additionally, the Residential Stretch Code has Electric Vehicle charging requirements for multifamily developments of 10 units or more. 

Last Updated: August 2017

Virginia’s Uniform Statewide Building Code (USBC) is mandatory statewide for residential buildings. Residential buildings must comply with the 2012 IRC; however, a few technical amendments were made to the residential energy code requirements and no significant improvements were adopted, rendering the residential code equivalent to the 2009 IECC. The state is currently reviewing the 2015 IECC, including weakening amendments for the residential code. 

Last Updated: July 2018

The 2015 Washington State Energy Code is a state-developed code that is mandatory statewide. The 2015 version of the residential code is based on the requires compliance with the 2015 IECC, with additional requirements providing an additional 17 reduction in energy use. The City of Seattle adopts an energy code that achieves greater savings than the Washington State Energy Code.

The Washington State Code Develpment Group was awarded the Jeffery A. Johson Award, in part to recognize their recent accomplishments.

Last Updated: July 2018

West Virginia's residential building code is mandatory statewide; however, adoption by jurisdictions is voluntary. The 2013 West Virginia Legislature passed a bill updating the state’s building energy code to follow the 2009 IECC for residential buildings. The new residential code became effective November 30, 2013.

Last Updated: July 2018

The state-developed residential code, referred to as Wisconsin Administrative Chapter SPS 322, Wisconsin Uniform Dwelling Code (UDC), is mandatory statewide for one- and two-family dwellings and incorporates the 2009 IECC with state amendments. These amendments are more restrictive for underfloor insulation for heated slabs. Local governments cannot modify the UDC and are required to enforce the UDC. 

Last Updated: August 2017

Wyoming's residential building code is voluntary. Known as the ICBO Uniform Building Code, it is based on the 1989 MEC and may be adopted and enforced by local jurisdictions. Some jurisdictions have adopted more stringent codes than the voluntary standard: the 8 most populated cities and counties in Wyoming have an energy code that meets or exceeds the IECC 2006 or equivalent. Teton County and Jackson are moving to the IECC 2012; Cheyenne adopted the IECC 2009; Casper, Rock Springs, and Gillette adopted a modified IECC 2006.

Last Updated: August 2017