Hello . Thanks for mapping.
A remark. You mapped a narrow white spot close to a mapped building as a building. What you mapped, was a sidewall rather than a building itself
Check this footage about mapping of buildings with visible sidewalls.

Keep an eye on complex buildings Especial the high rise (multi story) buildings and buildings which shows their sideviews  as well. Check this footage how to map these buildings 
https://www.youtube.com/watch?v=dsfUcslLtVc
https://drive.google.com/file/d/13RTwH7sChRWrG5bIjysF2ripBgh3F5l4/view?usp=sharing 

Best regards and keep mapping
