Mount Charles House, Mount Charles Crescent, Ayr

Mount Charles House is a villa dating to the later 18th century, with significant alterations to the front and a wing completed in 1829. The building is two storeys high with a basement, the basement being exposed on the sides and rear. The front elevation is built of ashlar stone, with rustication at the basement level; the original house and a later wing are of rubble and squared sandstone respectively. A prominent first floor cill course, eaves course, cornice, and blocking course are visible on the front elevation, along with strip pilasters. Windows are architraved on both ground and first floors, with cornices to the ground floor windows on the front elevation.

The northeast elevation, which serves as the main entrance, is five bays wide, with a recessed four-bay wing to the left. The central bay is slightly advanced and features an Ionic coupled-columned, pedimented porch sheltering a pair of glazed timber doors flanked by pilasters and sidelights, as well as a fanlight. A single window is positioned above the entrance at the first floor level. Regular window placement is found on the basement, ground, and first floors of the remaining bays; timber doors provide access to the basement on the left side. The recessed wing to the left features a timber door, an additional timber door in the re-entrant angle, a timber porch on the right at ground level, and four single windows on the first floor.

The southwest rear elevation exhibits a bowed bay with three single windows on each floor, alongside a square-headed entrance at the basement. A Venetian window is found at the basement level, a modern window on the ground floor, and a single window at the first floor on the bay to the right of the bow. Three later recessed bays extend to the right, distinguished by a band course above the ground floor openings. A stepped platt oversails the basement, incorporating a timber door, a small fanlight, and flanking single openings on each floor, with a bipartite window at ground floor level to the left.

The southeast side elevation reveals two bays belonging to the 1829 frontage, featuring a timber porch on the outer left and a single window aligned above the first floor. A single window is centrally placed, with a blind window above it on the first floor, and a smaller window is inserted at ground floor level between the two bays. The three-bay wing features a square-headed entrance, a letterbox fanlight, flanking single windows to the exposed basement, regular fenestration at ground level, and two single windows on the first floor.

The northwest side elevation displays a bipartite and single window at the basement level of the 1829 section, with a single window at ground floor and a blind opening at the first floor. A glazed timber door provides access to a lean-to entrance porch within the re-entrant angle. A later, square window has been inserted at the first floor. The earlier part of the house has two single windows at the basement, three single windows at ground and first floors, with a smaller, central window on the first floor and a blind window to the right. A later, central, dormer window is also present.

A variety of glazing patterns are used, encompassing modern plate glass, four-pane and lying-pane timber sash and case windows. The roof is slate-covered, with apex stacks and circular cans, and cast-iron rainwater goods are present. The interior of the house was not inspected during a 1999 survey.

A walled garden, constructed of coped rubble, is situated to the southwest of the house and is open to the south, overlooking the River Doon. It includes slate-roofed lean-to equipment sheds.