Here are a few techniques the data team uses to quickly trace buildings for OpenStreetMap. First, we use JOSM, the OpenStreetMap desktop data editor. We then install a couple custom plugins specifically for tracing buildings, like building_tools which lets us trace rectangular buildings in 2-3 mouse clicks and utilsplugin2 (see also) which is a collection of super useful tools for JOSM.
Here is a look at how the plugins work. Choose an area for building tracing and download data into JOSM. Check the imagery offset and adjust if needed.
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