Hello! Thank you for contributing to OpenStreetMap!

Sorry to come talk to you about this changeset of 4 months ago, but I've reverted it and re-done it in my changesets 169914060 (https://www.openstreetmap.org/changeset/169914060) and 169914062 (https://www.openstreetmap.org/changeset/169914062)*

The reason is that the buildings you've added in this changeset are very poorly drawn.

You seemed to have used exclusively satellite imagery (more specifically, Esri World Imagery) for drawing these buildings, which it isn't a bad thing on itself, but has caused many buildings to be incorrect.

Drawing buildings from satellite imagery is not easy, as shadows, colours and perspectives of the imagery and nearby trees or vegetation can make determining the presence and/or outlines of buildings very difficult.

In your commit, the vast majority of the buildings you've drawn are either incomplete (your shape does not match the real building, or it matches only a part of the building), oversimplified (you've drawn a complex building as a simple square or rectangle, when the real shape is more complicated than that) or outright incorrect (you've added several buildings very close together when in reality it's a singular building with a complex shape).

Over Catalonia, there are several satellite imageries available, like Mapbox Satellite, Bing, PNOA Spain, ICGC Ortophoto and Esri. Don't limit yourself to just using one, change to others if you have doubts on what you are seeing. What in one satellite imagery is hard to see, it may look clearer in another one.

Also, in Catalonia there's the ICGC Topographical Map layer which you can trace over and get the shapes of the buildings and other details. And in Spain, there's also the Spanish Cadastral layer that offers accurate building outlines. These layers are not perfect though (especially the ICGC Topo over rural areas), so you'll need to verify them with satellite imagery.

All of these layers are available to use as imagery in JOSM and other editors. Depending on your configuration, in JOSM you may need to go to the imagery settings.

Consider using these tips next time you add buildings from satellite imagery, by using several satellite layers you'll get better results than with just one.

Happy mapping!


* This is in two changesets because I've added many other things that didn't fit into a single changeset