The building’s main elements were large bands of Portland stone alternating with strips of windows spanning the whole building width, a glass wall that stretched the height of the building at 90 feet that lit each open-plan floor with natural light (from a side lightwell due to the densely built up area), against which the enormous Travertine marble staircase spiralled up the centre of the building, and the distinctive non-reflecting concave windows along the street level at front and back – the first in the country at the time.