Hi,
Welcome to OSM!

A relation is not required for a simple building, this has been deleted and the building mapping corrected. . see https://www.openstreetmap.org/way/1286513534

 Most buildings are 'square' meaning they have 90 degree corners. You can 'square' a selected object by pressing the 'Q' key. 

Most residential buildings here are houses, so a better tag would be building=house. 

Hope that helps. 