This new wing was built at the east end of and at a slight angle to the 1831 structure, the roof being copper and the exterior walls of the same masonry as the adjacent buildings, but, using more regulated block sizes and a flatter relief of pilasters and windows, as well as less detailing overall. The wing contains a separate entrance and ceremonial foyer with twin spiral staircases ascending to a piano nobile; the stairs have wood handrails with aluminum pickets and between them is a niche for sculpture. On the upper level is an event space, lounge, and sunroom with a terrace overlooking the St. Lawrence River. The former two areas are fully barrel vaulted and linked together by a continuous, narrow skylight in the roof under which crystal pendants of different lengths hang and transfer the natural light into the rooms. Interiors of the modern addition were designed by Quebec artist Madeleine Arbour, who was inspired by the colours of winter in Quebec, and use Canadian materials, including granite, walnut, and aluminum. The residence is furnished with pieces from the Crown Collection, mostly in New France style, antique furniture mixed with contemporary Canadian art.