"The design by Pelli Clarke Pelli keeps things simple, a tall box with glass on all sides except the south, where the floors that poke above a six-story neighbor would be clad in solar panels.Link.
The eye-catching feature would be the outer layer of green.
Planters contained by a trellis-like mesh would be attached between each floor, and each planter would hold a mix of vines so something is in bloom each month of the year. The vines would be trained to snake around cables that would form a sort of taut net around the glass box, with vertical cables spaced every 5 feet and horizontal ones stretched waist-high across each floor.
Not only would the vines provide a sort of environmental ornamentation, they'd help cool the exterior and reduce energy needs."
I'm not sure if this one even sounds good on paper.
ADDED: Many of the Chronicle reader comments at the link echo my concerns expressed in the comments here.