Well I suppose if you feel you could use a bit more room up around your upper back and shoulders but the shirts are baggy round your middle or lower back, you might need both darts and pleats. I get darts but no pleats myself.
I imagine there was a planning constraint about overlooking neighbours. I noticed the "indoor garden" on the ground floor has frosted glass, maybe for the same reason. Common problem with urban infill development in crowded places here in the UK - the preexisting buildings have a right to light and to privacy which means you end up with odd buildings without windows were you might want them.