In some more excellent news for architecture and tall buildings in SF, we learned this week that starchitect Renzo Piano, the man behind one of the best-loved new buildings of the last decade here, the California Academy of Sciences, has signed on to design a 37-story condo and hotel project at 555 Howard. Though still only in the initial stages of the design process, Piano and his Genoa-based firm have been hired by the developers of the site, Pacific Eagle Holdings and SKS Partners, and as the Chronicle's John King reports, Piano already sounds excited about the project.

Said the 78-year-old Piano, "If we do what we intend, it will be quite an amazing building, with a facade that breathes." He added, "We want something that is more than an object, more than a marble sculpture."

The site is a tricky one, hemmed in as it is by Tehama Street at the rear, and by a new elevated roadway, currently under construction, that will be the connection between the new Transbay Transit Center and East Bay buses going to and from the Bay Bridge. And the new Piano-designed tower would sit directly across Howard Street from the Transit Center.

As the Chronicle explains, the bus ramp will give them building some special prominence, though, because it will preserve the building's views to the south and west.

In the absence of any renderings just yet, Piano elaborates:

“We’re at the beginning of the job” — and indeed, the images being filed with the city’s planning department consist of little except evocative pencil sketches of a flat narrow shaft that is 37 stories on Howard Street but drops to 20 stories along Tehama Street, the alley at the rear. According to Piano, the idea is to wrap the tower in a double skin of glass with automated blinds in between that would add visual texture while controlling the heat and glare inside. He also hopes to embed the outer layer of glass with solar panels. ... The conceptual design lifts the bulk of the tower three floors above the street, with the ground floor opening not only to Howard Street but to [a public] park as well. Up high, Piano would love to see an open-air rooftop space shielded from the wind and accessible to people besides residents of the condominiums or guests of the hotel.

Things could still fall through, though. Piano had previously been tapped to design a much taller tower at First and Mission in 2006, but that project was ultimately scrapped in 2008 when the neighborhood got rezoned and the client sold the property.

And, news of him working on a Transbay District tower comes just as we heard of another setback to another piece of major architecture in the area, Jeanne Gang's striking, twisting condo tower at Folsom and Spear. This week we heard that Supervisor Aaron Peskin is trying to delay approval for the tower's extra 100 feet in height — it's currently zoned for 300 feet, but the developer and architect are asking for it to be 400 feet in order to improve upon the city's affordable housing mandate and build 40 percent of its units as below-market, 156 units in total. Peskin seems pissy that the project, 160 Folsom, was fast-tracked ahead of the Affordable Housing Bonus Program, despite both lingering in planning approval hell an equal amount of time.

Related: Here's The View From The Embarcadero Once Six Proposed New Towers Go Up Near Howard