An octagon house is exactly what it sounds like—an eight-sided building. A unique fad in residential architecture, they were particularly popular during the mid-19th century in the United States.
Early examples are Thomas Jefferson's Poplar Forest and William Thornton's Tayloe House, which is more commonly called The Octagon House. After the White House was burned down by the British during the War of 1812, President James Madison stayed in the Octagon House in Washington, D.C. It was here that the Treaty of Ghent ending the War of 1812 was signed. Later it served as the headquarters of the American Institute of Architects.
The English architect Thomas Ivory designed an octagonal church for the Unitarian congregation of Norwich U.K. in 1756 which is still extant and in regular use. It has exceptionally fine acoustical properties.
