Open Spaces Suck

Really you need both kinds of spaces and the freedom to choose where you want to be at any moment. Either (A) in the private, quiet hyper-focused space where you're doing hard stuff that requires holding a fragile chain of thought in active memory or (B) you're in the dynamic, open environment enjoying the stimulation of different voices and points of view. If you can only afford to build one of those spaces either build A or find an alternative for A like allowing people to work from home.