Austin’s energy code is based on the model codes IECC and ASHRAE; however, it includes many local amendments to make it considerably more stringent. Energy performance criteria are outlined for residential and non-residential buildings, addressing thermal envelope components and energy efficiency requirements for HVAC, hot water, lighting and auxiliary systems. The code allows prescriptive paths or simulated (reference building) calculation to show compliance.

Austin was the first city in the United States to establish a comprehensive voluntary energy efficiency program in 1970. Since then Austin has continued to improve energy efficiency requirements and in 2003 the standard became a mandatory code for the majority of building types. The current code and surrounding support systems includes a number of dynamic initiatives to improve energy efficiency; the "Zero Energy Capable Homes" by 2015 program, mandatory energy audits, energy performance rating and disclosure, air-tightness testing, commissioning, special requirements for public buildings and certification schemes to go beyond code.

General Information

Full Title of Code

Austin Energy Code

Year of Adoption


Date of Enforcement

Friday, October 1, 2010

Authority in Charge

Austin City Council


Link to Relevant Web Page

Remit of Code

Geographical Coverage


Code set at:

Regional/States Level


Coverage of Building Code:

  • Residential buildings
    • One family
    • Multiple family buildings
  • Public buildings
    • Offices
    • Hospitals
    • Educational buildings

GBPN Climate Classification:

  • Warm and Humid:
    Under the IECC Climate Zone Map defined as Climate Zone 2 (hot and humid climate).

Type of Building Code

Type of Building Code:

  • Model code, frame or actual code:
    Model Code with local ammendments. Austin’s energy code is based on IECC and ASHRAE 90.1, but they’ve adopted local amendments to make it considerably more stringent. Their code improvements are on a trajectory to make all new homes in the city Zero-Energy Capable by 2015.
  • Prescriptive Codes:
    Prescriptive measures. This is considered the simplest path. These requirements do not vary by building size, shape, window area, or other features. The 2009 IECC has a single table of requirements for insulation R-values and window and door U-factors and SHGC. There is a corresponding U-factor table that permits compliance of less common component types (e.g., structural insulated panels), albeit without any cross-component trade-offs.
  • Trade Off:
    Total building envelope UA (U-factor multiplied by area). This is the path predominantly used by the REScheckTM software. Based on the prescriptive U-factor table, it allows trade-offs whereby some energy-efficiency measures can fall below code requirements if balanced by other measures that exceed code requirements.
  • Energy Declaration:
    Many buildings that are sold now fall under the ECAD ordinance requiring an energy audit when sold. Large non-residential must be benchmarked using Portfolio Manager or the Austin Energy Business Energy Analysis tool.
  • Model / reference Building:
    Simulated performance (requires software programs). This path allows compliance if the home has a calculated annual energy consumption (or energy cost) equal to or less than that of a standard reference design that just meets the code’s prescriptive requirements. The method requires that heating, cooling and hot water system loads are included in the calculation. Renewable energy measure can now be included in this calculation.Called, the Total Building Performance method for commercial buildings.

Energy Covered

Basis for Energy Requirements:

  • Final Energy:
    Austin Energy primarily uses 'site' energy for its calculations.

Energy Uses and Functions Covered by the Code:

  • Heating
  • Cooling
  • Ventilation
  • Airtightness
  • Thermal bridging
  • Hot water
  • Building parts (lifts, pumps etc)
  • Lighting
  • Heat recovery
  • Natural ventilation
  • Solar protection
  • Daylighting requirements
  • Renewable Energy (solar, PV, others):
    Partially, no mandatory requirements but it is encouraged.


Enforcement Status of Code:


Type of Enforcement:

  • Local enforcement
  • Third party inspection
  • Post Occupancy control

On-site Inspections Occur

  • During construction
  • Post completion

Certification to Support Enforcement of Code:

  • Positive labeling for building beyond the minimum BC level
  • Inspection of boilers
  • Inspection of HVAC systems

Penalties for Non-compliance:

  • Refusal of permission to occupy
  • Refusal of permission to construct

Measures Supporting Enforcement:

  • Commissioning requirements
  • Airtightness testing required prior to compliance
  • Training of Inspectors

Values for New Buildings

Residential and Non-Residential Buildings.

GBPN Climate Classification

Cooling based

Coefficient for Comparison of Climate Zones


HDD (°C)951--
CDD (°C)1989--
U-Value (W/m²K)
Overall U-Value---
G Value/SHGC0.3-
Visible Transmission--

Other Requirements Set for:

  • Thermal bridge demands
  • Ventilation:
    Prescriptive equipment sizing and efficiency requirements.
  • Pressure testing for ducting
  • Domestic Hot Water COP - Heat Pump:
    Prescriptive equipment sizing and efficiency requirements and insulation requirements.
  • Value for airtightness:
    n50 is 7.0
  • Heat Recovery
  • Technical HVAC systems
  • Efficient Lighting

Code History and Future Targets

General Process in Setting Requirements:

  • Stakeholders are informed of future targets far in advance:
    Stakeholders are involved and informed in the development of the code.

Zero Energy Targets:

  • Definition of nZEB/ZEB/Plus Energy etc:
    Zero Energy Capable is defined as being so energy efficient that it is cost effective to install enough on-site renewable energy collectors to make the homes truly net-zero energy homes.
  • All end uses are not included
  • There is not a realistic roadmap in place
  • There is no national target date set for nZEB
  • Special Requirements for public buildings:
    New construction and major renovations of city buildings costing $2 million or more and requiring work in 5 major LEED rating categories must achieve LEED Silver certification; Requirement also applies to smaller renovations, interior finishing, and additions costing $300,000 or more and requiring work in 3 major LEED rating categories.
  • Links

Number of Earlier Codes


Current Defined Levels beyond Minimum Standard (present code)


Number of Future Aspirational Codes


Multiple set of data:

  • Levels beyond minimum:
    The city of Austin has numerous green building provisions within the city building code, with requirements that vary according to location, zoning designation and building type. The building standards rely on the Austin Energy Green Building Rating system and the LEED certification system as metrics. In some cases, developers have the option of achieving compliance under either of the two systems.
  • Year historic or aspirational codes (planned) :
  • Actual level of energy consumption in target
    • Relative target in percent:
    • Absolute target:
  • Levels set in energy frame
  • Primary Energy Performance Frame Residential:
    Zero energy capable by 2015.
  • Primary Energy Performance Frame Non-Residential :
    Zero energy capable by 2015.

Supporting Measures

Incentives/Rewards to Encourage People to go beyond Minimum Level?

There are a number of schemes available in the state of Texas, the following are specific to Austin. 1, Performance Based Incentives - Austin Energy - Commercial PVINcentive Scheme. 2, Utility Loan Programs - Austin Energy - Residential Energy Efficiency Loan Program and the Residential Solar Program. 3, Utility Rebate Programs - Austin Energy - Commercial Energy Management Rebate Program, Commercial New Construction Efficiency Rebates, Free Home Energy Improvements Program, Multi-Family Energy Efficienc

Involvement of Stakeholders in the Development of Codes

Very involved. The community is more forward thinking that most in Texas and the community supports a relatively aggressive approach to sustainability.

Level of Training Provided to Stakeholders Following Implementation of Code?

Online resources and free courses and seminars.

Provision of Appropriate Information for General Public

Online resources and free courses and seminars.

Supporting Certification Schemes

Austin Energy Green Building Program (AEGB) has a number of certification schemes for different types of buildings; AEGB Single-Family Rating System, the AEGB Multi-family Rating System and the AEGB Commercial Rating System. All based on a 5-Star rating system, 5 being the most efficient. U.S. Green Building Council -Central Texas Chapter.

Codes Free to Access?

Code is avilable free to the public.


Compliance assessment