John Kohnstamm, SIOR, joined Capacity Commercial Group LLC as principal of the Portland-based commercial real estate brokerage firm. He will be part of the company's office product team, along with principals Scott Madsen, who left Cushman & Wakefield in July of last year to join the company, and Jeff Falconer and Mike Nye, who both left Trammell Crow to co-found Capacity Commercial Group in May of 2004.