Hi there, I've just been valdating this HOT area near Mandalay,and noticed you mapped some buildings by following the roof shapes visible from the aerial photos.

Unfortunately that's not the correct way, since the photos may be taken not perpendicularly or distorted during the geo-referentiation process.

The proper way for mapping buildings is to reproduce their footprint (or try to do so): that's still an approximate mapping, but it assures more precision.

If you need to reproduce square or rectangular shapes, you can draw them approximately and then adjust them with the "Orthogonalize" function of you editor (shortcut is 'Q' in both JOSM and iD).

Thanks for your work, and happy mapping!  :-)
Max