Likely to have built in the early to mid-C17, Hafod Gethin is the original farmhouse at Plas Gwyn, relegated to ancillary status after the present house was built in the late C18. The stables/hayloft was probably added at this time or shortly afterwards, but the cowhouse appears to belong to the first phase. The original 2-room plan of the farm house is likely to have been created by a timber partition below the cross beam immediately to the left of the entrance; the present stone cross wall to the right of the entrance is a later insertion, presumably erected when the timber partition was removed. The existing staircase may have been put in at this time.