[mhays]

I like the concept of green roofs, but opponents are correct that they can be expensive. They involve added weight, plumbing, and maintenance/accessibility. There's ongoing risk of leaks including accidental penetrations. Those things can be relatively easy in some buildings and harder in others.

For example in the proposed tower above, maybe the roof line becomes vertical screens around a flat roof. But mechanical equipment probably goes up there too, with a thin shell or screening around that. What tradeoffs and added costs would be necessary? Or is there enough area in the podium and setback roofs to handle it all there? Does the building need to taper via steps vs. angles?