Arnold insisted his client retain the original black and white marble floors in the entryway. “Those historical details are something you can’t replicate,” the designer explains. “When you walk into the house, it has a sense of presence and age.” To complement the room’s classic good looks, Arnold placed a custom metal table by Micah Farrer of Obsidian Ironworks, a vintage burl-wood stool and a Hector Finch sconce with leather shade.