For the Jewish festival of Sukkot, which starts Wednesday evening and which Jews celebrate by erecting (and eating in) a temporary booth called a sukkah, Congregation Beth Elohim, in Brooklyn, commissioned a community sukkah designed by B-an-G Studio, a new architecture firm. The firm’s principals, Babak Bryan and Henry Grosman, won the people’s choice award in last year’s Sukkah City competition, held in Union Square. For Beth Elohim, Mr. Bryan and Mr. Grosman designed a sukkah made of 3,000 pieces of wood, which members of the congregation put together. To complete the design, temple members are painting 1,500 laser-cut cardboard leaves in colorful bursts of red, orange and yellow. The leaves will be affixed to the sukkah’s frame of wood and bent-steel spines.