Methodology
Version 1.0 · effective 2026-08-15
Each definition below carries its formula, its source series, how often it moves, how it is classified, and where it stops being reliable. Vertical-specific indices are added to this page as they are published.
Publishability gate (anti-doorway rule)
publishable = tierAllows(city, product) AND metricsRows(city, product) > 0
- Inputs
- City tier (1–3) and product tier (1–3). Tier 1 cities carry all products; tier 2 cities carry tier 1–2 products; tier 3 cities carry anchor products only.
- Refresh cadence
- Evaluated on every request, at render time.
- Provenance
- Deterministic rule, not a measurement.
- Known limits
- The gate governs indexation, not accuracy. A page can pass the gate and still be backed by baseline seeds — which is why provenance labels exist alongside it.
Observation series
series = append-only log of dated observations; nothing is overwritten
- Inputs
- Named public sources and Data Desk field observations, each stored with its own date and source label.
- Refresh cadence
- Reviewed on the published cadence for each series.
- Provenance
- Observed. Any derived figure built on top is labelled modelled.
- Known limits
- An observation describes what was recorded on a date in a market. It is not a quote, a price, or professional advice for a specific property.
Provenance classes
How these figures were produced
- Observed — Recorded directly from the cited source series, unadjusted.
- Modelled — Derived arithmetically from observed inputs using the published method; not a market quote.
- Baseline seed — A documented starting estimate awaiting first observation. Treat as an order-of-magnitude figure only.
Revision log
v1.0 ·
First publication: provenance classes (observed / modelled / baseline seed) and the publishability gate that governs which market pages may be indexed.
Method changes are versioned here. Data corrections are logged separately.
Questions about the method
What does a provenance label actually mean?
Observed means the figure was recorded from a named source on a stated date. Modelled means it was computed from observed inputs using a formula published on this page. Baseline seed means it is a documented starting estimate that has not yet been replaced by an observation.
Why are some markets missing pages?
A market page is indexable only when the tier rule allows it and at least one real data row backs it. Empty pages are never published to fill out a sitemap.
Can I reproduce these numbers myself?
Yes — that is the point. Every formula is stated in full and every input is either cited to a public source or shown on the page.
Not advice — Envirolor is a data publisher. We do not perform, certify, or supervise professional work, and nothing here is a quote, an engagement, or professional advice. Figures are indicative benchmarks for comparison and must be confirmed with a qualified professional before you rely on them. About Envirolor