Quadrangle: A new trophy office tower with windows that actually open? The architect fills us in.

The Commission of Fine Arts' final review of Quadrangle Development Corp.'s proposed trophy-class office tower coming to 1301 Pennsylvania Ave. NW came with high praise. It is an "elegant and simple design," the commission said, featuring "innovative technical aspects of contemporary European architecture." One of those aspects: operable windows, a rarity in today's commercial office market. I reached out to Jahn, the Chicago-based studio responsible for the design, to learn more. "We...