Externally it was unremarkable, but the classicising domed hall surrounded by galleried aisles and apsidal ends was something new in assembly rooms, and brought its architect immediate celebrity. The design was exhibited at the Royal Academy, private commissions followed, and at the age of 26 Wyatt found himself a fashionable domestic architect and on 27 August 1770 an Associate of the Royal Academy. His polished manners secured him friends as well as patrons among the great, and when it was rumoured that he was about to leave the country to become architect to Catherine II of Russia, a group of English noblemen is said to have offered him a retaining fee of £1,200 to remain in their service. His major neoclassical country houses include Heaton Hall near Manchester (1772), Heveningham Hall in Suffolk (circa 1788–99), and Castle Coole in Ireland, as well as Packington Hall in Staffordshire, the home of the Levett family for generations, and Dodington Park in Gloucestershire for the Codrington family. On 15 February 1785 Wyatt was elected an Academician of the Royal Academy, his diploma work being a drawing of the Darnley Mausoleum.