Data Dictionary

The HPXML Data Dictionary (BPI-2200-S-2013 Standard for Home Performance-Related Data Collection v2.3) provides a standard vocabulary of data elements necessary to provide a general description of a whole house or single measure energy efficiency upgrade for reporting, rebate, and basic quality assurance purposes. Each of the data elements defined in the dictionary can be transferred using the HPXML standard transfer protocol. The dictionary includes terms related to:

  • Contractors
  • Customers
  • Buildings, building components and building systems
  • Energy conservation measures
  • Energy consumption
  • Energy savings (estimated and actual)

The dictionary also includes several smaller datasets for specific use cases, for example, information collected during the audit and completion of a whole-house program. These datasets, with required data elements, can be found here.

Aligned with Industry Standards

HPXML is the most widely used implementation of the Department of Energy’s Building Energy Data Exchange Specification (BEDES). BEDES is a taxonomy of terms, definitions, and field formats created to facilitate the exchange of information on building characteristics and energy use for the commercial, multifamily and residential industries.

Terms in HPXML will also be mapped to the Real Estate Standards Organization's (RESO) Data Dictionary (fall 2018). The RESO data dictionary standardizes terms used in Multiple Listing Services (MLS) nationwide. When completed, this alignment will facilitate the auto-population of a home's energy efficiency features, including score and labels, into local MLS systems. Auto-population is an efficient way to introduce energy efficiency data into real estate transactions. 

Continued Improvement

The HPXML Data Dictionary is designed to grow with the industry. The HPXML working group meets quarterly to discuss updates and revisions to the data standard. Recommendations for adding new or changing existing data elements or enumerations can be proposed on Github.

Program Adoption of HPXML

Arizona Public Service

Austin Energy

Build It Green

Efficiency Vermont


NYS Energy and Research Development Authority

Pacific Gas and Electric Company

PSEG Long Island

Salt River Project

San Diego Gas & Electric


Southern California Edison

United Illuminating