Saratoga Springs, NY: The Building Performance Institute, Inc. (BPI) is inviting public input on BPI 2100-Home Performance Related Data Transfer, also known as the HPXML Transfer Standard. BPI’s Data and Modeling Standards Technical Committee (DM-STC) has approved the release of draft Version 5.0 for a 45-day public comment period, which will close on March 22, 2026. 

HPXML is a data transfer protocol designed to support the exchange of information across different software systems using an open, technology-neutral solution. It is developed through BPI’s ANSI-accredited standards development process, with openness, transparency, and consensus at its core. 

The NLR OpenStudio HPXML Modeling Toolkit relies on HPXML, and several of the schema updates in Version 5.0 were driven by changes to that platform. BPI and NLR are coordinating to align the release of OpenStudio HPXML with the HPXML 5.0 release. 

Developed by BPI’s HPXML Working Group, which reports to the DM-STC, the HPXML Transfer Standard is intended to improve data collection efficiency, reduce time and costs, and support the transfer of residential energy efficiency data across a broad range of industries. 

More than 20 programs use HPXML. A full list can be found here: HPXML Compliant Software 

The HPXML Data Transfer Standard, also referred to as a “schema,” follows the Semantic Versioning 2.0 specification to indicate changes and updates. Version numbers follow a pattern of Major, Minor, and Patch (e.g., 2.3.0).   

The current draft HPXML standard is considered a major update, moving from Version 4.2 to Version 5.0. 

A complete list of changes to the HPXML standard can be found here:  

HPXML Version 5.0 draft: Release v5.0 Release Candidate 1 · hpxmlwg/hpxml · GitHub 
 

• Add DENH (DOE Efficient New Home) enum #452 

• Add SpecificLeakageArea infiltration element #455 

• Allow ElectricPanel/HeadroomSpaces to be negative #456 

• Allow medium light for wall/roof color #457 

• Allow stone veneer for wall siding #458 

• Add not present/other/unknown choices #451* 

*Breaking Change 

To submit comments on HPXML, please download the BPI Standards Comment Form.   

Completed forms must be submitted to standards@bpi.org by March 22, 2026, in order for comments to be considered by the DM-STC.