This mansion house was built in 1867 by Richard Owens, architect of Liverpool, for the Liverpool industrialist John Roberts, father of the first Lord Clwyd. Richard Owens was surveyor to John Roberts' father, David Roberts, before starting his own practice which specialised in chapel building. Bryngwenallt is a rare surviving example of a domestic building by this prolific architect.

It is a Gothic style small country house built of snecked limestone, now partly pebbledashed and painted, with slate roofs, banded with green fish-scale slates. The entrance is set under a tall four-storey crenellated tower with double lancets at the top stage, and a taller circular stair turret in the N corner. The door is set behind a four-centred arch on granite nook shafts with limestone capitals and there is a canted stone-framed oriel balcony above. It has mullioned and transomed timber windows with external staff mouldings throughout.

It is listed as a notable example of a mid-Victorian industrialist's mansion and as a house designed by a significant chapel architect.

Source:- Cadw listed buildings, NJR 07/01/2010