Llansannor House is a two storey late Regency style villa dating from c.1845. Built of local rubblestone with brick framed openings but normally rendered and painted overall, with a Welsh slate roof. It is of double depth plan with a range across the rear and two wings projecting to form a 4-bay south front. The ground floor is covered on three sides by a timber verandah with square posts, this is glazed in on the west side, and on the east side has a pedimented entrance with clustered piers.

A gasworks was marked on the 1897 OS map and was visible until the 1964 OS map. The gasworks would have supplied gas to light the house and any other significant buildings.

Reference: Cadw listed buildings database.
RCAHMW, 2010.