Requirements for ENERGY STAR® Version 2.5 and 3

Energy Star Versions 2.5 and 3.0 -- Prescriptive vs. Performance Path

There are two paths that can be followed in order to achieve certification under ES Version 3.0. If the home meets the Benchmark Home Size in the table below, the builder can follow the Prescriptive Path to acheive qualification. However, if the Conditioned Floor Area of the home is greater than the benchmark based on the number of bedrooms in the home, the applicant must follow the Performance Path.  (For example, if the home has three bedrooms, the total conditioned floor area of the home must be 2200 sq. ft. or less to follow the Prescriptive Path.)  Many builders may voluntarily follow the Performance Path with all their homes because of its additional flexibility, as explained below.


Bedrooms in Home12345678
Conditioned Floor Area1,0001,6002,2002,8003,4004,0004,6005,200


The Prescriptive Path is a single set of measures that can be used to construct the home without the need for computer modelling.  All measures must be followed exactly, without tradeoffs, in order to acheive ENERGY STAR performance levels. The National Program Requirements highlight the ENERGY STAR Reference Design used for this path.   Additionally, the Home Energy Rater will verify that the requirements in the following checklists have been executed correctly by the builder and subcontractors.

  • Completed Thermal Enclosure System Rater Checklist
  • Completed HVAC System Quality Installation Contractor Checklist
  • Completed HVAC System Quality Installation Rater Checklist
  • Completed Water Management System Builder Checklist

The Performance Path utilizes energy modeling to determine an ENERGY STAR HERS Index Target. The Performance Path includes a size adjustment factor to incentivize the design of smaller homes, but it also offers optional performance measures which can be traded off as appropriate to achieve the ENERGY STAR HERS Index Target. This Index Target will be different for each home--it is a sliding scale dependent on the size, location, and orientation of the specific home.  

Under the previous ENERGY STAR Version 2, the home had to meet a minimum HERS Index of 85. Within the new performance guidelines, these homes will now often have an Index Target in the range of HERS 70-80 (or 20-30% better than a conventional home at HERS 100).  Acheiving ENERGY STAR under the new Performance Path requires that the completed home meets or exceeds the ENERGY STAR HERS Index Target previously determined by the Rater's energy modeling.  In addition, the same four checklists above must be completed and verified by the Home Energy Rater.


Differences between ENERGY STAR 2.5 and 3.0 -- Implementation Timeline

ENERGY STAR Versions 2.5 and 3.0 are largely the same.  While the Builder/Rater team is required to complete all of the above checklists in both Versions, the only specific requirements that are binding for V2.5 are the “Fully-Aligned Air Barriers” and the “Air Sealing” sections of the Thermal Enclosure System checklist.  All other lists must be submitted but will not be enforced until V3.0 has been fully implemented (1/1/2012).

 V3 Implementation schedule

Any home permitted prior to April 1st, 2011 can qualify under ENERGY STAR V2 if the home is completed by Decemeber 31st, 2011.  Every home permitted on or after April 1, 2011 must qualify under the transitional V2.5 guidelines.  All homes completed and/or permitted on or after 1/1/2012 will be required to follow Version 3.0 in its entirety, including all checklists described above.  Check the ENERGY STAR Version 3 Guidelines for the most recently updated version of these checklists.  

Additionally, the NCEEA has created a "Fillable PDF" version of these ENERGY STAR checklists for input from a laptop or mobile device in the field.  These can reduce paperwork and streamline documentation not only for Home Energy Raters, but also for Builders and HVAC Contractors.  You can find them on our website under Rater Resources.

Visit the ENERGY STAR® website to access the newest V3 Checklist Guidebooks and additional resources.