The Federal Courthouse annex in Des Moines has the distinction of being the lowest costing federal courthouse due to Neumann's design-assist delivery. This method saved approximately 100 days time in the schedule and 10% of the overall project cost. The annex was built with structural steel on auger cast piles. It has a precast exterior with limestone and curtain wall, and a single ply membrane roof. The building, which was awarded an Energy Efficient Design distinction, is cooled by a central chiller and heated by electric VAV boxes. Both courtrooms were outfitted with state-of-the-art sound and communications systems, and the building has an extensive security system and underground parking for the judges.