Comments Open for BPI-2400 Annex E Through January 26th

Saratoga Springs, NY:  The Building Performance Institute, Inc. (BPI) has extended the public comment period for ANSI/BPI-2400-S-2015: Standard Practice for the Standardized Qualification of Whole-House Energy Savings Predictions by Calibration to Energy Use History, also known as the “Delta Standard”.

Annex E: Alternative Asset‐Based Savings Calculation with Insufficient Energy Use Data (BPI-2400 Annex E) will be available for public comment through January 26th, 2024, previously January 16th. Comments on this informative annex will be accepted for review during the extension period.

The Delta Standard specifies the requirements and process for the calculation of standardized predicted savings using approved building energy simulation software.

This standard specifies a process to calibrate the model to the actual energy use of the home, using an approved building energy simulation software tool and actual energy bills. It provides a set of criteria for use in the final calculation of standardized estimated savings that may be considered in compliance with this standard.

The Delta Standard is referenced in the HOMES Energy Efficiency Rebate Program, part of the Inflation Reduction Act of 2022 (IRA). BPI has updated the standard to provide more flexibility to contractors while maintaining consistent and conservative savings estimations.

Like all BPI standards, the Delta Standard was developed by a working group of subject matter experts who represent a wide variety of interest categories and geographic locations. BPI’s Data and Modeling Standards Technical Committee (DM-STC) convened a new working group to create this latest update.
BPI-2400 Annex E was approved by the DM-STC for public review and is currently undergoing public comment period as defined under BPI’s standards development process.

Comments on BPI-2400 Annex E are being solicited from stakeholders and the public. The full Delta Standard will undergo review and revision by the DM-STC in 2024.

To view the standard, visit: Standards Under Review

Comments may be submitted to through January 26, 2024.