DAC was commissioned by Boeing to lead construction on their building 74-320 — a new 60,850 square foot addition to the company's manufacturing facility in Helena. The building is primarily additional manufacturing space, with included equipment rooms , storage rooms, and office space. The building's structure is a manufactured metal building by Nucor Building Systems. The building envelope is typical, with a metal siding wall assembly, blanket insulation, vapor barrier, and full height metal liner panels, The roof consists of vertical seem roof panels, blanket insulation and vapor barrier. The foundations are SNK Milling Equipment Foundations. Boeing installed three 5-ton bridge cranes and two 7-ton bridge cranes over the manufacturing space, along with a full area floor covered with a high performance floor coating.