Switzerland keeps a federal register of every building: the Federal Register of Buildings and Dwellings (GWR), run by the Federal Statistical Office and updated by the municipalities. In Lausanne it gives a construction year for most buildings and a construction period for some others.

How the map was made. The official cadastral survey of the canton of Vaud is not freely available, so building outlines come from OpenStreetMap. They carry no register identifier. Each register building is therefore placed in the outline that contains its register coordinate: a spatial join, not a join by identifier. 11,921 of 13,747 register buildings found an outline.

What the colours mean. 9,437 of 11,681 outlines contain a building with a documented year. 286 contain one with only a register period and are coloured by the display period closest to it. OpenStreetMap often draws a terrace as one outline: 1,318 outlines contain several register buildings and take the year of the largest. 1,958 outlines contain no register building, often sheds and garages, and appear only as outlines.

Limits. Register buildings without an OpenStreetMap outline, mostly small non-residential structures, are not drawn. The register records when a building was built, not later conversions. The map shows the buildings standing today. Register snapshot: 08.10.2026.