This project includes design-build services to replace windows in Building #220 of the Rock Island Arsenal. The work involves removing existing steel-framed windows and replacing them with a new aluminum-framed, energy-efficient window system. The windows, which must match those used on previous projects, are located on various building sides and on different floor elevations. The project also includes concrete repair and modifications to window openings as necessary for the new system. Disruption of manufacturing operations throughout the process must be minimal.