Despite its bad rap for fog and wind, San Francisco is leading the charge when it comes to rooftop spaces. Will the rest of the US take note? Shorenstein dangled a private rooftop in front of Twitter as a negotiation tactic to plant its HQ at 1355 Market. Now the Twitterati enjoy the private, lush landscaped top, where they can play bean bag toss, nosh on delicacies like quail from the kitchen, sunbathe, and attend intimate, live concerts. Tenants with roofs around town think it's an amenity with great value because it gives them a fresh-air refuge and allows them to commune outside of a formal office space.

People are conscious of being outdoors and roofs are a big retention and attraction technique these days, Shorenstein's Jim Collins tells us. 505 Howard's scenic oasis with Bay Bridge views helped score Neustar as an anchor last year. Pembroke wants to draw more tech to its newly-purchased 100 Cal, in part, via a sizable rooftop deck. S.F. is leading the pack on the residential front, too. Most of Garden Village Apartments in Berkeley will be topped in food-producing gardens that'll grow local and organic produce. S.F.-based EBS worked with Nautilus Group to conduct a sustainability, financial, and structural feasibility study for the rooftop farms.