 Ayrton's most notable public building from his years with Simpson was the old Wembley Stadium, a simple structure in reinforced concrete which they designed together, built between 1921 and 1923 for the British Empire Exhibition at Wembley Park of 1924 to 1925.It had echoes of the Olympic stadium of 1908 at White City.Simpson received a knighthood for their Exhibition work, while as a result of it Ayrton came into an association with the project's civil engineer, Owen Williams, and this led to their working together on the design of Williams's bridges in Scotland.