How We Evaluate Systems

How Systems Are Evaluated

Every system is measured against the same scoring rubric: can the assembly dry itself out (Drying Ability), can you inspect it when something goes wrong (Inspectability), and does it minimize and disclose its chemical load (VOC Tier). Those three axes produce the verdict. The rubric is frozen — the axes and their definitions were set before the first system was scored, and they do not change to fit a result. A change to an axis definition is a formal revision that triggers re-scoring of every existing evaluation.

The verdict follows the scores, never the reverse. At least one recommended system is scored openly, including its limitations, precisely so a reader can confirm the rubric drives the verdict rather than the other way around. Contractor feasibility and material documentation are also assessed and discussed in each evaluation, but they are not scored on the badge — they describe practicality, not indoor-air performance.

What "Evidence-Informed" Means

Evidence-informed is a deliberate phrase. It means our guidance is built from the best available evidence — published research, government and standards-body guidance, manufacturer safety data, and documented field experience — while being honest about where that evidence is incomplete. When something is unknown, contested, or depends on individual factors, we say so. We use bounded, defensible language: "lower-risk," not "safe"; "may reduce," not "eliminates." Overconfident claims that later prove wrong do more damage to trust than careful ones, especially for the readers who rely on this most.

Two and only two citation forms appear on our evaluations: an inline source with enough specificity to verify, or an explicit label that a statement is Good Air Homes' evaluative judgment. See the evidence policy for how sources are weighed, and the spray foam scorecard for the method applied end to end.

Conflict of Interest & How We Are Funded

Independence here is not a disclaimer mentioned once — it is the mechanism that makes the evaluations worth reading. We do not sell building materials. We do not accept manufacturer sponsorships or advertising. We publish no affiliate links. No company can pay for a favorable evaluation, a modified standard, or preferential placement.

Revenue comes from two sources only: a one-time homeowner package fee, and certification fees paid by builders who choose to participate. Builders pay to be held to the standard, not to influence it. Because no part of our income depends on recommending any particular product, there is no commercial reason to soften a verdict — and the free site names material categories and performance specifications only, never brands, so a recommendation can never double as a sale.

Corrections Process

When we get something wrong, we correct it in public. Anyone can report an error. A correction that changes a claim, a score, or a verdict is logged with the date, what changed, and why, and the affected page's review date is updated. If a correction changes an axis definition in the rubric, every existing evaluation is re-scored — that is the cost of keeping the rubric frozen and consistent, and we pay it rather than letting two pages disagree.

Review & Update Cycle

Every page carries a visible "last reviewed" date. Pages are re-examined when new research or field evidence warrants it, and substantive updates move the review date and are logged. We would rather a page say plainly that it was last reviewed on a given date than imply a currency it cannot support.

Who Is Accountable

This standard is written and maintained under named authorship rather than as anonymous institutional copy, because attributable expertise is more accountable — and, frankly, more trustworthy to a reader deciding whether to rely on it. Evaluations are reviewed and signed by Zen Watcher, founder of Good Air Homes. The founder's reason for building this is on the About page.

Reviewed by Zen Watcher, Good Air Homes.