Energy Systems Laboratory's Emissions Reduction Calculator

The Energy Systems Laboratory at Texas A & M University is developing an Emissions Reduction Calculator (ERC) that is an accurate, easy-to-use, web-based tool. The ERC will allow Texans to quantify pollution and money saved per energy efficiency measure installed.

The calculator takes the consumer through five easy steps showing the results of different configurations of energy efficiency measures such as thicker insulation, high performance windows, alternative materials and Energy Star appliances. It calculates the potential energy and utility bill savings. For example, 12 to 16% energy savings can be obtained by combining a cool roof application with ENERGY STAR appliances. Such Green Building characteristics impact all aspects of the residence. For example, the cool roof application would amplify the duct sealing/HVAC standard savings.

For more information on the calculator, go to

Getting Credit for Energy Savings

Texas cities can receive full credit for energy efficiency measures, which are frequently the least-cost way to reduce pollution.

The US Environmental Protection Agency and the Texas Commission for Environmental Quality (TCEQ) have issued guidance documents (
stating that energy efficiency measures do reduce emissions in the Houston and Dallas/Fort Worth implementation plans. These agencies are giving credit for a variety of measures, such as the energy code, to meet Texas clean air plan (the State Implementation Plan).

Additional energy savings can be achieved in both residential and commercial buildings above the current energy code practices. Improvements in the building envelope, roofing materials, lighting, heating and air-conditioning and appliances can provide an additional 15-20% savings to the home or business owner. Builders should be encouraged to go beyond the energy code and to document these savings.

The Emissions Reduction Calculator will give homeowners and builders a tool to determine the cost effectiveness of energy efficient measures and their pollution reduction effect. However, cities and counties need the reported data on these implemented measures to be able to receive credit toward their own compliance attainment actions. Therefore cities and counties should take steps to ensure that

  • Various energy efficiency and emission reduction methods taken by builders and homeowners are reported to the state,

  • Enforceable measures such as building code modifications that affect every building in a jurisdiction and are verified by an inspector or plan reviewer are reviewed and reported to the TCEQ,

  • Each county or the state requires the collecting of energy rating data on all new homes and the filing of such data in the county courthouse or with the county clerk.

These items would insure Texas receives all due credits for emissions-reducing energy savings. Many new homes are built just outside the city limits and are not inspected by city building inspectors. Senate bill 5 allows for a third party inspector or the builder to rate the energy used by the building and give the rating to the homeowner. Unfortunately, unless the performance rating is collected and submitted no credit will be given toward the state's pollution reduction requirements. These rating sheets must be given to the Energy Systems Lab at Texas A & M University for credit.

  • Voluntary measures that affect just a single house or building over and above the building code and other requirements should also be reported through the Energy Systems Laboratory.

The forms that will assist cities and counties in collecting the data are available on the Energy Systems Lab website at

Implemented improvements that go beyond the requirements of the present code can be used to balance out the more expensive traditional methods of reducing pollution. For example, it is estimated that a traditional method of reducing Nitrogen Oxide (NOx) such as stack scrubbers, in the Houston area is expected to exceed $46,000 a ton by 2008. It may be cheaper to subsidize the buying of highly efficient air conditioners for residential and commercial structures than to add pollution controls to a power plant. Thus it may prove to be far less expensive to reduce NOx pollution through building efficiency.   back to top  back to Cut Costs

Policy Recommendations to Obtain Pollution Credits

Texans on both a public and private level can implement actions that will move the state toward EPA standards for healthy air quality through pollution reduction. These actions require little or no funding by the state or by the cities and counties. Such actions have the added benefit of saving taxpayers money in both the long and short term. Policies to support these actions are:

  • Those measures, such as building code modifications, that affect every building in a jurisdiction and are enforceable and are verified by inspector or plan reviewer should be reported to the TCEQ,

  • Adopt a county resolution requiring the energy rating form from ESL be given to builders at the sewage permit stage of construction and be collected at closing. The form can be downloaded at,

  • Require a copy of this form to be filed with the county clerk at the time of closing. Such forms should also be sent to A&M’s Energy Systems Laboratory annually,

  • Use the ERC to identify potential energy savings and emissions benefits,

  • Create a market for emissions credits and allow for the aggregation of credits for sales. Such emissions credits could be transferred between cities or sold and used by others to meet their emissions reduction obligations, and

  • Adopt the Texas Green Building Program, or equivalent program as a way to encourage, rate and receive credit for homes that go beyond the code.

A legislative initiative that accomplishes all these goals except the market for emissions credits has been introduced into the current legislative session. 
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