Validate an HPXML file against the current schema and use-case rules
domain: hpxml.nlr.gov · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Create an account and obtain an API key at hpxml.nlr.gov (the HPXML Toolbox) — do not use the old hpxml.nrel.gov host; DNS for the entire nrel.gov domain stopped resolving May 29, 2026 after NREL was renamed National Laboratory of the Rockies (NLR).
POST the HPXML file as the request body to https://hpxml.nlr.gov/api/<API_KEY>/ (e.g., curl -X POST -d @audit.xml https://hpxml.nlr.gov/api/<API_KEY>/).
Parse the JSON response, which reports pass/fail per schema version and per use case (e.g., HPXMLSchema, AuditUseCase, UpgradeUseCase, HomeEnergyScoreUseCase, BPI2101UseCase, IRA-related use cases).
Cross-check the target HPXML schema/data-dictionary version against the authoritative BPI HPXML Standard (BPI-2100 transfer protocol, BPI-2200 data dictionary) and the specifications published at hpxmlonline.com before locking a version for production use.
Re-run validation after any schema-version bump, since use-case rule sets (especially IRA-related ones) are versioned separately from the base schema.
Known gotchas
Any code or docs referencing developer.nrel.gov or hpxml.nrel.gov are stale post-May 2026 — DNS no longer resolves and there is no redirect; update to the nlr.gov equivalents.
The API key is free but tied to a user account for abuse prevention, not anonymous — don't hardcode it in shared/public code.
HPXML data-dictionary versions (e.g., 4.1.0 vs 4.2.0) can carry field-name differences; validate against the same version your downstream consumer (HEScore, rating software) expects.
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