You've got precise traces with good sense of proportion (between tall and wide), are very correct archithectonic illustrations for the SSP diagram (if is what you're looking for).
but...
I'll be honest (not rude intention at all), looks as plain 2D objects (very correct) but, if you want to search for a different stroke/style/results
Look to some real photo of the building you draw...some like google street view image:
https://goo.gl/maps/W7ndkfH9xdroD37w9
what we see?...
perhaps... a bit of reflections, shadows, textures, color tones/ transitions, transparency...
Not same color/tone on the lower levels to as seen on top
well...
When a drawing try those effects, 2D "seems" like having other dimension...
https://skyscraperpage.com/diagrams/?searchID=94872573
like you did here...
https://skyscraperpage.com/cities/?buildingID=131737 or
https://skyscraperpage.com/cities/?buildingID=131730