The collaborative aspect of SANAA that Hawthorne and the jury praises is certainly nothing new, but that each retains their own individual practice is very unique. Many partnerships splinter as two or more designers and their egos do battle. Thom Mayne received the prize in 2005, but for a long time Morphosis was him and Michael Rotondi, who formed ROTO Architects in 1995. It's cliche but oftentimes true to say that a firm does not have room for more than one great designer. I think SANAA manage by allowing their own practices to exist and be treated equally; SANAA does not take precedence over the others, even though the commissions may get more press. But what is also important about this three-part structure, and is something that makes their choice for the Pritzker a little more complicated, is how the projects of each practice are not so easily distinguishable from the others. To be sure SANAA's commissions tend to be larger, but the minimalism, pristine surfaces and complex spaces are present in all their output. The award is given to Sejima and Nishizawa, but it can also be seen as a validation of all their work, whichever name gets the formal credit.
Previous Sejima/Nishizawa/SANAA coverage on my web pages:
:: Dior Building (Sejima)03-31 Correction: Christopher Hawthorne does indeed mention the separate practices of Sejima and Nishizawa: "Both continue to operate their own smaller, separate firms."
:: Moriyama House (Nishizawa)
:: New Museum of Contemporary Art (SANAA, building)
:: New Museum of Contemporary Art (SANAA, project)
:: Onishi Hall (Sejima)
:: Rolex Learning Center (SANAA)
:: SANAA Houses (Sejima, Nishizawa, SANAA)
:: SHIFT: SANAA and the New Museum (SANAA)