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State Profile

Code Type: Commercial Residential
Current State Code 2015 IECC and ASHRAE 90.1-2013 2015 IECC with Amendments
Effective Date
Adoption Date
State Amendments No Yes
State Code Analysis*
Enforcement Mandatory Statewide Mandatory Statewide
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
2009 IECC

Model Code Savings Potential

Statewide Savings Potential (2010-2030) Residential Commercial
Cost $8.93B $3.31B
Energy (primary) 803MBtu 436MBtu

Consumer Cost Savings

Consumer Cost Savings Residential
per Home
per 1,000 ft2
Annual ($) $303 $105
Annual (%) 17.7%
Life-cycle (30 year) $4050 $1590
Simple Payback 4.8 years 0.0 years
Positive Cash Flow 0.6 years


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

Additional Information



    Commercial and Residential Construction

    Before 1999, except for state-owned buildings, Texas had no mandatory state-wide energy code for either residential or commercial buildings.  No attempt had been made to adopt mandatory energy codes on a statewide basis.  The state encouraged voluntary adoption of codes and provided training for code officials and home builders.

    In June 2001, Texas adopted its first mandatory statewide energy code, based on the 2000 IECC including the 2001 supplement for residential, commercial, and industrial construction.

    When ICC published the 2006 edition of the IECC, Texas opted not to adopt this latest edition based on the technical analysis and recommendation of Energy Systems Laboratory of Texas A&M University which determined the new edition was not as stringent as the current codes when applied in Texas.

    On March 9, 2009, a bill was introduced in the Texas State Legislature that would adopt the latest energy efficiency editions of the IRC and the IECC.  On April 1, 2011 the 2009 IECC became effective for all commercial and residential construction and on January 1, 2012 the energy efficiency chapter of the 2009 IRC became effective for all single-family residential construction.

    State-Funded Buildings

    For state-owned buildings, Texas originally adapted the ASHRAE/IES Standard 90.1-0989 into the Texas Design Standard.  This standard, which originally went into effect in June 1989, was updated in February 1993.  In 2002, Texas adopted ASHRAE 90.1 as the energy code for commercial and multi-family residential.  Since 2002, Texas has continued to adopt the latest ASHRAE 90.1 Standard.  On September 1, 2011 ASHRAE 90.1-2010 became the effective standard for state-funded buildings.

    For state-owned residential buildings, Texas adopted the Texas Design Standard and later adopted the 1993 CABO MEC.  Pursuant to Texas Government Code 447.004, the State Energy Conservation Office adopted by reference the 2003 IECC effective September 1, 2005 and more recently updated the code to the 2009 IECC effective June 1, 2011.

    On June 16, 2015, Texas Governor Greg Abbott signed HB 1736 into Texas law. This moved the state's single-family residential code from 2009 code to the 2015 International Residential Code (IRC), Chapter 11. All local jurisdictions must comply with the new code by September 1, 2016. The new Texas code includes an Energy Rating Index compliance option. The Texas state legislature modified the 2015 IRC required Energy Rating Index scores to a set of scaled scores that increases in stringency over time. The required index scores in Texas are: Climate Zones 2 and 3 is 65 or lower from September 1, 2016 to August 31, 2019, a score of 63 or lower from September 1, 2019 to August 31 2022, 59 or lower score after September 1, 2022. In Climate Zone 4, a 69 or lower score from September 1, 2016 to August 31, 2019, a 67 or lower score from September 1, 2019 to August 31, 2022, and a score of 63 or lower after September 1, 2022.

    State-Owned/Funded Buildings

    The Texas State Energy Conservation Office adopted by reference the ASHRAE/IESNA Standard 90.1-2010 for state-funded buildings.  The code applies to new construction or major renovation projects, except low-rise residential buildings, with a design assignment made on or after September 1, 2011.

    The residential chapter of the 2009 International Energy Conservation Code was adopted for state-funded new construction or major renovation projects of low-rise residential building with a design assignment made on or after June 1, 2011. 

    Texas requires state government departments to compare the cost of providing energy alternatives for new and reconstructed state government buildings and for certain construction or repair to energy systems and equipment. The governing body must determine economic feasibility for each function by comparing the estimated cost of providing energy for the function using conventional design practices and energy systems with the estimated cost of providing energy for the function using energy efficient architecture and design or alternative energy devices during the economic life of the building. If the use of alternative energy devices for a particular function (including space heating and cooling, water heating, electrical loads, and interior lighting) is economically feasible, then the use of alternative energy devices must be included in construction plans.

    Alternative energy is defined to include solar, biomass, wind, and geothermal energy sources. This section of Texas law (Texas Government Code 2166.403) was originally put in place in 1995. It was amended in 2005 (S.B. 982) to add geothermal to the list of eligible resources and designate the Texas State Energy Conservation Office (SECO) as the authority for approving any methodology or electronic software used to make the required comparisons. As of April 2009, SECO accepts one software program (RETScreen) for this purpose. Further details are available on the program website. Texas Govt Code 2166.401.

    Adoption Process

    The Texas State Energy Conservation Office (SECO) by rule may choose to adopt the latest published editions of the energy efficiency provisions of the International Residential Code or the International Energy Conservation Code for residential or commercial buildings.  When new ICC codes are published, Energy Systems Laboratory (ESL), a division of Texas A&M University, reviews the new editions to ensure stringency of the IRC and IECC compared to existing Texas energy codes.  ESL then provides SECO a written recommendation based on analysis and public review.  If ESL recommends adopting the new code, a stakeholder meeting is held to gain input and a draft of the new rule is published for public comment.  After comments are reviewed, SECO then makes the decision whether to adopt the latest energy codes in Texas.

    Local municipalities or counties may choose to adopt local amendments to the energy code provided that the amendments do not result in less stringent energy efficiency requirements than the adopted state-mandated energy codes.

    For state-owned or -funded buildings, the provisions are adopted through the state's administrative process of publication, public comment, and hearings.

    Enforcement Process

    For state-owned or -funded buildings, the cognizant state agency enforces the code. For all other buildings, the cognizant local government enforces the code. If a jurisdiction adopts an energy code, the code is enforced through the permit/inspection process for new construction and additions. Depending on the size of the jurisdiction, the same individual may perform plan reviews and inspections.

    Compliance Process

    For state-owned or -funded buildings, the design professional submits a completed compliance statement and certification to the cognizant state agency that the design is in compliance with the Texas Design Standard or the MEC (as applicable based on the building type).

    For all other buildings in jurisdictions that have adopted energy provisions, compliance is determined through the permit process. Typically, plans are submitted and reviewed and then buildings are inspected. After successful completion of this process, the building department issues a certificate of occupancy.