P.S. 1 and the Museum of Modern Art have just announced that Brooklyn-based urban design and planning firm Interboro Partners are the winners of the 2011 Young Architects Program. Now celebrating its 12th year, the honor means designing what by now is widely recognized as the liveliest party space of the summer, the outdoor plaza of P.S. 1 in Queens.

“Simple materials that transform a space to create a kind of public living room and rec room are trademarks of this young Brooklyn firm,” said Barry Bergdoll, MoMa’s Philip Johnson chief curator. “Interboro is interested in creating elegant and unpretentious spaces with common materials. Their work has both a modesty and a commitment quite at odds with the luxury and complex computer-generated form that has prevailed in the city in recent years.”

The firm has also been selected this year as one of the eight firms participating in the Emerging Voices series at the Architectural League. Much of their work focuses on urban challenges, from completing a neighborhood development plan for Newark, the first in decades, to a temporary park at Canal and Varick streets, Lent Space, with mobile trees, seating and walls.

Meanwhile, in Rome, a companion program called YAP_MAXXI in an outdoor space at the entrance of the new Zaha Hadid-designed museum, was also launched. Roman architects, stARTT, have been selected as the first-up in a partnership between MoMA P.S. 1 and the overseas institution, a model of a collaboration that could easily expand to other countries in no time. StARTT’s entry “Whatami” appears to be a series of discrete and turf-covered hillocks with Hadid-like curves constructed of various recyclable materials including straw, geo-textiles, and plastic.

Recycling, in fact, was a key theme this year as Interboro also canvassed local libraries, greenmarkets, senior and daycare centers to see who might be able to use the rope and other materials when summer is over.