These apartment buildings are in the middle of the former East-Berlin. They are just down the road from the Stasi headquarters. I don’t know how old they are, but to me the look very simple and functional, with an emphasis on cost and not on amazing or interesting design.
They remind me of my old lego set, looking like they could have been assembled from really big lego blocks.
Yes I can see what you mean by lego blocks, they remind me of government apartment housing we use to have here.