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BPI HPXML Standard Seeking Input During Public Review Period

posted at 2025-07-14 09:25:00
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Saratoga Springs, NY: The Building Performance Institute, Inc. (BPI) is seeking input from the public on BPI 2100, Home Performance Related Data Transfer (the HPXML Transfer Standard). BPI’s Data and Modeling Standards Technical Committee (DM-STC) has approved the release of the draft Version 4.2, for a 45 day public comment period ending on August 28, 2025. 

HPXML is a data transfer protocol that can be used to exchange information between different software systems using an open, technology-neutral solution developed through BPI’s ANSI-accredited standards development procedures, with openness, transparency, and a consensus-based approach at its core.  

NREL’s Open Studio HPXML Modeling Toolkit relies on HPXML, and some of the schema changes have been motivated by the changes to this platform. BPI and NREL are working together to synch up the release of Open Studio HPXML with the HPXML V4.2 release. 

Constructed by BPI’s HPXML Working Group, which reports to the DM-STC, the HPXML Transfer Standard can be used to improve efficiency of data collection, reduce time and cost, and allow for transfer of residential energy efficiency data across a wide range of industries.  

Many programs use HPXML, including: 

  • Arizona Public Service  
  • Austin Energy 
  • Efficiency Vermont 
  • NYSERDA 
  • Pacific Gas & Electric  
  • Pearl Certification 
  • PSEG Long Island 
  • Salt River Project 
  • San Diego Gas & Electric 
  • SoCalGas 
  • Southern California Edison 
  • United Illuminating 

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 minor update, moving from Version 4.1 to Version 4.2.  

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

HPXML Version 4.2 draft: https://github.com/hpxmlwg/hpxml/releases/tag/v4.2-rc3 

 

  • Vehicles, including electric vehicles, and their chargers in #403 and #436 
  • ElectricPanel: add BranchCircuits and ServiceFeeders to evaluate needs for panel upgrades in #435 
  • Bowstring Roof for manufactured homes in #432 
  • Heat pump water heater voltage and mixing valve setpoint in #431 
  • adding ClothesDryer/DryingMethod so a heat pump clothes dryer can be indicated in #444 
  • Measure Taxonomy in #428.  
  • Clarify sameas attribute in #437 
  • Four (4) new fields in the BPI2400Inputs for reporting in HPXML: #448 and #449  

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

Completed forms must be submitted to standards@bpi.org by August 28, 2025 in order for comments to be considered by the DM-STC.