20 Main Street, Glamis

20 Main Street in Glamis is a late 18th century, two-storey, three-bay house that forms part of a regular terrace on the southwest side. The building is constructed from coursed and squared rubble.

The northwest elevation, facing Main Street, features a modern boarded timber door with a three-pane fanlight in the center bay. There is a window to the right and a bipartite window to the left, with regular fenestration on the first floor.

On the southeast elevation, there is a door to the left of center, flanked by small windows. There is another window off-center to the right on the first floor, and a piended timber dormer window above the bay to the left. An ancillary structure projects to the right of center.

The northeast elevation, facing Nicol's Close, has a door on the right at ground level within a gabled section, with an ancillary structure adjoining to the left.

The windows are timber sash and case, featuring 4- and 12-pane glazing patterns. The roof is covered with purple slates, and there are coped brick stacks with cans.

The ancillary structure is a long, low building made of rubble with an Angus stone slated roof, featuring a variety of openings on both the southwest and northeast elevations.