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State Profile

Code Type: Commercial Residential
Current State Code 2018 IECC and ASHRAE 90.1-2016 2018 IECC with Amendments
Effective Date
Adoption Date
State Amendments Yes Yes
State Code Analysis*
Enforcement Jurisdictional Jurisdictional
Can use COM/REScheck Yes Yes


Commercial Residential
Current Model Code ASHRAE Standard 90.1-2013 2015 IECC
Yes Yes
Previous Model Code
ASHRAE Standard 90.1-2010
ASHRAE Standard 90.1-2007
Previous Model Code
2012 IECC
2009 IECC

Model Code Savings Potential

Statewide Savings Potential (2010-2030)
Energy (primary)

Consumer Cost Savings

Consumer Cost Savings Residential
per Home
per 1,000 ft2
Annual ($) $1097 $593
Annual (%) 21.1%
Life-cycle (30 year) $12613 $9710
Simple Payback 4.3 years 0.0 years
Positive Cash Flow 0.9 years


Code Type: Residential Commercial
Field Study No No
Training Program No No

Additional Information



    The first Hawaii energy code was based on ASHRAE/IES Standard 90-1975. It was mandated by state legislation in 1978 and adopted by three of the four counties in the state in 1978 and 1979. Although the law was mandated, there was no penalty provision.

    In 1989 the Department of Business, Economic Development, and Tourism hired a consultant to formulate standards for a new HMEC for commercial and residential structures. The code was finalized in 1993. The HMEC is based on ASHRAE/IESNA 90.1-1989 with modifications to accommodate Hawaii's climate. Changes include the deletion of all space-heating requirements and changes in the building envelope and water-heating requirements.

    In 1994, the legislature enacted Act 168 requiring counties to adopt efficiency requirements based on ASHRAE/IES Standard 90.1-1989 by October 24, 1994, for new and renovated commercial buildings.

    On August 8, 2001, the city and county of Honolulu, containing 80% of the state's population, adopted portions of ASHRAE 90.1-1999 and required R-19 or equivalent in new residential roofs.

    As of March 6, 2006, the Hawaii DBEDT/Energy Efficiency is in the process of developing the "Tropical Energy Code" which will draw from the Guam Energy Code, ASHRAE 90.1-2004, and design considerations unique to the tropics.

    On May 21, 2007, Governor Linda Lingle signed SB795 SD2 HD1 CD1, which created a nine-member state building code council to establish a state building code based on the International Building Code.

    In May 2009, the Hawaii County Council adopted the 2006 IECC with state-specific amendments. Among them, the new code gives options for roof insulation including cool roofs, advanced ventilation, and low emittance roofs by testing or specification. It also has stricter requirements regarding pools as well as mandatory HVAC and other system commissioning.

    On October 13, 2009, the Hawaii Building Code Council approved the 2006 IECC with state-specific amendments as the statewide energy code. The code will become law once an Administrative Directive is approved, which is expected to be signed soon by Gov. Linda Lingle.

    The counties of Hawaii are free to modify the statewide code, as long as the codes they adopt are at least as energy efficient. Recent updates to the various county code processes:

    • Hawaii County adopted the amended-2006 IECC state code in May 2009
    • Maui County is expected to adopt the state code soon.
    • Honolulu County is expected to adopt the state code soon
    • Kauai County adopted 2009 IECC in January 2010.

    On July 14, 2015, the State Building Code Council adopted the new HEC based on the 2015 IECC/90.1-2013 with amendments.

    State-Owned/Funded Buildings

    No later than December 15, 2021, the design of all State building construction must comply with the 2018 IECC and attached amendments to the code, in accordance with HRS 107-27.

    Enacted in June 2009, HB 1464 addressed energy efficiency requirements for existing public buildings. By the end of 2010, state agencies must evaluate the energy efficiency of all existing public buildings that are larger than 5,000 square feet or use more than 8,000 kilowatt-hours (kWh) annually. Opportunities for increased energy efficiency must be identified by setting benchmarks for these buildings using Energy Star Portfolio Management or another similar tool. Buildings must be retro-commissioned every five years. Further guidance on the requirements described in HB 1464 will be provided by January 1, 2010.

    According to USGBC, on June 26, 2006, Governor Lingle signed HB #2175, thus requiring each state agency to design and construct buildings to meet the LEED Silver certified level, or a comparable standard. The law applies to all new state-owned construction of 5,000 square feet or greater, including K-12 public schools.

    Adoption Process

    The Hawaii Building Code Council, charged with adopting the ICC suite of codes, follows the ICC code cycle. When an updated Hawaii Model Energy Code is approved by the Council, it goes through a small business review and public hearing process. When approval is obtained at both levels, the Governor approves, and it becomes an Administrative Directive. Such directives apply only to State Government buildings, including Hawaii's approximately 300 public schools and charter schools.

    The counties may adopt the model code as is, or modify, provided it is at least as energy efficient as the model code. The energy code bills are introduced to the county councils and are heard by the councils at three hearings. Thereafter, the bills are signed into law by the mayors. There is usually a 60 or 90 day lead-in time after the signing.

    Enforcement Process

    For all commercial buildings and all residential structures over three stories in height, field inspections by the County Public Works Department (Design & Construction Department in the city and county of Honolulu) are conducted during the established inspection process mandated by the building code. No special procedures are required to enforce the energy requirements.

    Enforcement for state buildings is handled by the County Building Departments. State buildings are specifically cited in the state law that mandated which counties must adopt the HMEC or equivalent.

    Compliance Process

    Low-rise residential buildings (for counties adopting the residential portion of the HMEC) may use a single prescriptive envelope path. Plans are submitted when required by the County Public Works Department. Local jurisdictions require that a registered architect or engineer review and stamp the plans and provide a written statement indicating compliance with the code requirements. However, local jurisdictions still have the obligation to oversee the actual plans that are submitted during the established plan review functions.