Moray later served on the Treasury Commission for Scotland, as did Alexander Bruce, now Earl of Kincardine. Bruce reported to this Commission as a revenue collector, and benefited from the patronage of its members. The Commission had responsibility for the King's Works, and in 1667 Bruce was appointed Superintendent and Overseer of the Royal Palaces in Scotland. Four years later he was made Surveyor General of the King's Works in Scotland, with a salary of £3600 Scots (£300 Sterling, or £  in ), for the purpose of rebuilding Holyroodhouse. In March 1671, Bruce was part of a syndicate which bought the rights to collect taxes over a five-year period, paying £26,000 Sterling (£  in ) for the privilege. As such, it would appear that Bruce was not only the architect of Holyroodhouse, but one of the principal financiers of the £21,000 project.