sentences:  The building's tilted, dark-blue stainless steel cube, constructed by A. Zahner Company, slices into the old substation's brick, making visible the relationship between the new and the old.Libeskind's design preserves the defining features of Polk's old building, including its brick façade, trusses, and skylights.36 diamond-shaped windows light the top floor of the metal cube, known as the "Yud", which hosts sound and performance based exhibitions.