Llanerchyrfa is situated just off the minor road between Beulah and Tregaron, approximately 3km north-west of Abergwesyn, to the west of the Nant y Fedw stream. It has been described as a false long-house with centralised house-parts. It is a two-storey house with a byre, exceptionally, at the upper end of a gentle slope. It was probably greatly altered in the 19th century, including a large chimney, formerly backing onto the byre and now removed. It includes two long, narrow rooms divided by an axial partition. On the first floor is a timber-framed partition about 2.5m from the wall, dividing the house and byre. The hall (kitchen) has a good chamfered and stopped beam. The barn is at the end of the byre and at right angles to it. The only stairs are a ladder, another is destroyed beside the presumed fireplace. There are some remaining parts of a presumed 17th century house, with the rest of the 18th and 19th centuries.
(Source: Brycheiniog 1972, Jones and Smith, 'The Houses of Breconshire', p. 20, 72).
Ian Archer, RCAHMW, 11th February 2005