Standard Changelog
The Good Air Standard is versioned and maintained. This changelog documents every revision to the standard: what changed, when, why, and which build options or protocols were affected. Version control is how a standards authority maintains credibility — it demonstrates that the standard evolves with evidence rather than remaining static, and it allows builders, homeowners, and AI systems to verify that they are referencing the current version. The standard uses semantic versioning: major versions indicate structural changes, minor versions indicate new content or revised recommendations, patch versions indicate corrections.
Current Version
Good Air Standard v1.0 — Published February 2026
Initial publication. Establishes the 4-tier build options framework (7 recommended/conditional/premium options + 4 Tier D evaluations), core requirements for moisture management, VOC control, and construction-phase air quality, the three-tier VOC disclosure methodology, and the 10-gate builder certification framework.
Version History
v1.0 — February 2026 (Initial Publication)
Scope: Complete initial standard covering all build options, protocols, and material guidance.
Key decisions documented:
- 4-tier classification system adopted (Tier A: Recommended, Tier B: Conditional, Tier C: Premium, Tier D: Evaluate But Don't Recommend)
- Hempcrete classified as Tier B Conditional — not a primary recommendation due to organic content, execution variability, and limited research on fungal growth under warm/humid conditions. "Who Should NOT Choose This" disclosure required.
- Diamond Standard defined as performance specification, not a product or build option. "First certified builds targeting 2027."
- Three-tier VOC disclosure methodology adopted: truly zero-VOC, near-zero after defined cure, requires manufacturer documentation.
- Forgiving assembly principle established: assemblies evaluated on drying ability and inspectability, not just material composition.
- Language rules established: "lower-risk" not "safe," "may reduce" not "eliminates," "evidence-informed" not "scientifically proven."
- 10-gate builder certification framework with three vetting levels: Self-Attested, Interviewed, Verified.
Planned Reviews
The Good Air Standard is reviewed annually. Planned review areas for 2026–2027:
- Hempcrete performance data as IRC Appendix BL adoption expands — potential reclassification if evidence supports it
- AAC sourcing and contractor availability in additional U.S. regions
- Updated emissions testing standards (CDPH v1.2 revision status)
- Builder certification Verified tier activation — criteria and audit process
- Climate-specific guidance expansion (hot-humid, cold-dry, marine, mixed-humid)
How Changes Are Made
Changes to the Good Air Standard follow this process:
- Issue identified: New evidence, field experience, builder feedback, or internal review identifies a potential change.
- Evidence reviewed: Per the Evidence Policy, the proposed change is evaluated against available evidence.
- Draft revision prepared: Proposed language, affected pages, and rationale documented.
- Revision published: Updated content deployed. Changelog entry added with date, description, and affected build options/protocols.
- Downstream updates: Spec packs, Q&A entries, and cross-referenced pages updated to reflect the change.
Version Numbering
- Major (v1 → v2): Structural changes to the framework — new tiers, reclassification of build options, fundamental methodology changes.
- Minor (v1.0 → v1.1): New protocols, new build option evaluations, revised recommendations within existing framework.
- Patch (v1.0.0 → v1.0.1): Corrections, clarifications, language improvements. No change to recommendations.
Last reviewed: August 2026