 Although Thomas Coke oversaw the project , he delegated the on @-@ site architectural duties to the local Norfolk architect Matthew Brettingham , who was employed as the on @-@ site clerk of works . Brettingham was already the estate architect , and was in receipt of £ 50 a year ( about 7 @,@ 000 pounds per year in 2016 terms ) in return for " taking care of his Lordship 's buildings " . William Kent was mainly responsible for the interiors of the Southwest pavilion , or family wing block , particularly the Long Library . Kent produced a variety of alternative exteriors , suggesting a far richer decoration than Coke wanted . Brettingham described the building of Holkham as " the great work of [ my life ] " , and when he published his " The Plans and Elevations of the late Earl of Leicester 's House at Holkham " , he immodestly described himself as sole architect , making no mention of Kent 's involvement . However , in a later edition of the book , Brettingham 's son admitted that " the general idea was first struck out by the Earls of Leicester and Burlington , assisted by Mr. William Kent " . 
