45 Mountstuart Road, Rothesay, Bute

46 Mountstuart Road is a double villa designed by John Duncan and dated 1877, showcasing a symmetrical 2-storey, 4-bay layout in the style of Alexander Thomson. It forms the end of a symmetrical terrace and is grouped with single-storey, single-bay entrance porches that are recessed to the outer left and right. The villa is constructed from yellow sandstone ashlar with polished ashlar dressings, featuring a raised base course and timber bracketed eaves above the ground floor canted windows. The eaves are raised and stepped, with overhanging timber bracketed eaves. The ground floor has square-headed windows with chamfered reveals, while the first floor features round-arched windows with keystoned and architraved surrounds, supported by pilastered sandstone mullions. The sides and rear are finished in random rubble sandstone.

On the north (entrance) elevation, there is cast-iron brattishing above three-light canted windows at the ground level in the outer bays. Above these are bipartite windows aligned with single square-headed windows on the first floor, offset to the left and right. The ground floor also has bipartite windows in two bays flanking the center, with a decorative cast-iron bracketed balcony above. A centrally located bipartite window on the first floor is flanked by single windows. The entrance features 2-leaf timber panelled doors set in round-arched surrounds within the recessed porches on the outer left and right, complete with plate-glass fanlights.

The villa has 2-pane timber sash and case glazing and is topped with a graded grey slate roof, retaining some original rainwater goods. It features corniced ridge and wallhead stacks, along with various decorative cans.

The boundary walls consist of a coped random rubble wall along Mount Stuart Road, with an oval datestone set in a segmental-arched surround at the center, inscribed "Royal Terrace 1877" and surmounted by an anthemion and flanking consoles. The square-plan gatepiers have a raised base course and consoled broken pediments on each facet, with armorial panels centered below and topped with ball-finials. Various cast-iron pedestrian entry gates complete the setting.