Designed by John Adam in 1760 to be seen on the approach road to the House, it has a Palladian front similar to that of the House and is Category B listed. Its setting is enhanced by the line of Wellingtonias planted behind it by the 3rd Marquess of Bute. It has also served as accommodation for Coachmen and Chauffeurs, reflecting the changes in modes of transport. Much renovation is required for this building.