DwellDelta
In development
Australia & New Zealand · property change monitoring
Property data is full of confident numbers nobody can trace. DwellDelta watches change across Australian and New Zealand property — sale and rent, residential to warehouse, from national down to a single lot — and every figure it shows can be followed back to a frozen contract, a snapshot, and the exact delta between them.
Measured geography
Under every watch is real geography, and for five NSW postcodes it goes all the way down to the surveyed lot — the legal shape of one block of land, as the state's own land registry records it. Below is a fragment of postcode 2000, drawn from the same file the product loads, at the same precision. It is markup in this page rather than a picture: nothing is requested to draw it, and it renders with scripting switched off.
Real surveyed cadastre for postcode 2000 — one of only five NSW postcodes where this product holds lot geometry, and the one thing on this page that can be checked against a government dataset. Every line here is a lot boundary or a road centreline from the NSW Land Parcel and Property Theme; the rule at the lower left is 200 m. No market observation is shown. There is no price, rent, listing count or delta anywhere in this drawing, because the product holds none that are real — the geography is the only measured thing in it.
Contains NSW Government data © NSW Department of Customer Service (Spatial Services), licensed under CC BY 3.0 AU.
What it watches
One measure is shown at a time; any number of context layers can sit under it. Each carries its own provenance, and a layer with no source behind it says so on the layer itself rather than quietly drawing nothing.
Zoom bands run global → ANZ → postcode → suburb → street → lot, and the delta window moves between 1, 3, 6, 12, 18 months and the full series. The bands are not evenly covered: postcode boundaries are Australian only — 2,641 of the ABS's 2,644 postal areas — suburbs are NSW only, and streets and lots exist for five NSW postcodes. New Zealand has country and region boundaries and nothing finer.
How it works
A number is only as good as the path back to where it came from. There are four links, and each one is an immutable record that the next one cites.
Mission walk005-property-monitor-local-v1 · verifier
sha256:5c47706cbf07c3eec6fe3db7538c0daf769d0de134b01cacda962a3877383cf7
Methodology
8 released repositories are read at receipt-pinned commits. Their package manifests are checked byte by byte, then semantic identities are followed from the frozen schema through browser evidence.
Every release carries a receipt naming its commit, its tag, its checksum and the checks its owner ran — including the ones that failed. A release that fails a check says so and is superseded by a later one; published records are corrected forward, never rewritten.
Coverage
One map, both countries. New Zealand is served from the same board and the same contracts as Australia — not bolted on, and not a separate product. The geography behind it is not equal yet: 24 of the 32 subjects are Australian, and New Zealand has region boundaries where Australia has postcodes and NSW has suburbs, streets and lots.
Boundaries, roads and parcels come from vendored public data — Natural Earth, ABS postal areas, NSW land parcel and road centreline themes. These are measured, attributed, and not invented. The optional Basemap layer is the one that is not vendored: its tiles come from OpenFreeMap over OpenStreetMap data, under ODbL, which requires attribution.
Every price, rent, listing count and history value shown today is synthetic. No provider feed is authorised and no real market observation has been published.
Where coverage stops, the board says so on the panel rather than leaving a gap a reader would fill in themselves. A board that hides its own edges invites a false read.
Capability language
Each capability sits in exactly one state, and the words mean the same thing everywhere they appear.
Immutable releases with receipts, across all eight repositories.
The synthetic end-to-end evidence chain runs and is verified.
No service is operated for anyone: no hosted run, no scheduled job, and no address that reaches the product. Serving this static page from a host deploys the page, not the product.
No provider feed, real property fact, customer record, or delivered alert.
Known limits
Evidence: integration walk005-local-5c47706cbf07c3ee · snapshot
snap_walk001_nsw_2000_20260702 · change chg_cca4dc9a586e7f9bb574da86