 The house was unfinished when Seymour fell from power, but a correspondence survives, dated between November 1548 and June 1549, which shows Thynne directing the plans.He also played a part in the building of Seymour's Somerset House in London.At Longleat, Thynne took thirty-seven years to design and build his own great neo-classical house with four facades, Doric, Ionic, and Corinthian pilasters, and regularly spaced bay windows.