Cadastral change detection: parcel splits, merges and new parcels
snoop shows how Swiss cadastral parcels changed over any range of months you pick. It compares cadastral snapshots and paints every change on the map, color-coded by type, so you can see where parcels were split, merged, newly created or removed.
Six change types
- Split: one parcel became several
- Merge: several parcels became one
- New: a parcel that did not exist before
- Removed: a parcel that no longer exists
- Re-ID: same footprint, new EGRID
- Resized: same EGRID, changed boundary or area
Splits and merges are derived from parcel geometry. Re-ID and Resized are off by default, so the main events read first.
Pick a date range
A slider over a month-by-month bar chart selects any run of months. Choose whether the range counts by change date, taken from the official survey records, or by publication date, when the change first appeared in the swisstopo data. The header shows how many changes the range holds.
What you can do
- Click a change to see the EGRIDs before and after, the area change, the zone code and the municipality
- Filter by change type, building zones only or a minimum area
- Browse the change list, search by municipality, canton or EGRID, and sort by date
- Show a density heatmap of where changes cluster
- Share a link to a change, or track the parcel in your records (PRM) when signed in
Frequently asked questions
Was this parcel split or merged?
Search the address or click the parcel on the map. If snoop detected a change there, the detail panel names the type (split, merge, new, removed, re-ID or resized), lists the EGRIDs before and after, and shows the old and new area with the change date.
How are changes dated?
By change date, the validity date of the update in the official survey records, or by publication date, when the change first appeared in the monthly swisstopo data. Survey updates often reach the public data months later, so recent months fill in over time.
Where does the change data come from?
snoop compares successive snapshots of the official cadastral survey data from swisstopo and derives each split, merge or new parcel from that comparison. For legally binding information, check the land register.