East Trethellan Farmhouse and Attached Outbuildings

East Trethellan Farmhouse and attached outbuildings is likely from the late 17th or early 18th century, although it incorporates earlier fabric and has been altered, currently undergoing restoration. The farmhouse is constructed of coursed squared granite and uncoursed granite rubble, with a slate roof and brick chimneys. It follows a T-plan, comprising a single-depth, two-unit main range with a rear stair turret. The main range is two storeys high and five bays wide, exhibiting a symmetrical design. The front wall features unusual masonry with roughly-squared granite blocks of varying sizes laid in a regular pattern, with some very large blocks forming the base to the right of the front door. It has a central doorway with a six-panel door fitted with a long strap hinge on the bottom rail, and regularly spaced square windows, all with splayed voussoirs, and now fitted with 16-pane sashes. Rebuilt gable chimneys are present. A lean-to kitchen is attached to the left end, and an outbuilding extends to the right.

At the rear, the stair turret and the wall to the left are of uncoursed rubble with large quoins, while the wall to the right largely matches the masonry of the front, with the exception of a lean-to addition at ground floor. A window in the stair turret is similar in style to those at the front, and there is a doorway to the left, alongside a small window at first floor level to the right.

Inside, a large rectangular fireplace with massive jambs and lintel is found in the first bay, incorporating an integral bread oven. Stone-flagged floors are present. Current restoration work includes bead-moulded beams, panelled doors and partitions and a staircase, these reproducing details from original features or fragments found on site.

The attached outbuildings include a short range continued to the right and a long projecting wing, both two-storeyed and of uncoursed granite rubble with quoins and corrugated sheet roofs. The continuation, formerly a mill with water power through the rear wall, is three bays wide and symmetrical, with central doorways on both floors and altered windows. The wing has irregular openings, including four doorways (the third being a reduced wagon entrance with a long granite lintel), a window between the first and second floors, and two small windows above. A hipped roof is present, alongside a lean-to addition to the end of the wing.