16 Gelli-deg

16 Gelli-deg is a cottage forming part of a terraced row, largely altered in the 18th century. Originally, it comprised a three-bay farmhouse with a small service range set back to the right. The farmhouse's left bay forms part of No. 16, while six later cottages, built in two blocks, now make up the remainder of No. 16, No. 17, No. 19, and No. 21.

One bay of No. 16 is the left bay of the original farmhouse, which was a two-storey, three-bay building with end stacks (the left-hand stack is now gone). The front is painted stucco with raised surrounds to the openings, and the roof is slate. A two-pane sash window is on the ground floor to the left; the front door is 20th century. The rear wall is of painted rubble stone, with large boulders at the base. A rendered section with a door to the right provides access to the upper part of the original house, now part of No. 16, and a lean-to pantry with a catslide roof extending over. An upper floor has one small, four-pane casement window above the door.

The first block of three cottages, comprising the main part of No. 16 and No. 17, is painted rendered with a slate roof and two stacks: one between Nos. 16 and 17, and another at the left end. The eaves and ridge line are higher than the earlier building to the right. The cottages originally had a single-window range, with a small window under the eaves, a larger window below, and a door to one side. No. 16 has a door to the left of the windows; the other two cottages originally had paired doors between the windows; the door to No. 17 survives, while the door to No. 18 has been replaced with a window. The glazing in No. 16 is plastic, replacing original sashes, and the front door is 20th century. The rendered rear wall has a 20th-century window inserted at ground floor level.

In 1988, the original farmhouse section (now part of No. 16) was found to have oak double-purlin roofs with pegged collar trusses. There was a lobby entry by the right gable, next to a large fireplace. A partition, originally stone only on the ground floor and not tied-in, now separates Nos. 15 and 16. Stairs were positioned against the partition to the rear. The ground floor had oak floor beams spaced at intervals of approximately 1.2 metres. The original farmhouse, potentially a one-room plan with ladder or steep-step access to the upper room, had joisted floors with axial joists, and ground floor flagstones.