A lawyer and writer, he continued to live at Ardress House, where he made further changes including the addition of a dining room that could only be reached via an external door.

[10] The alteration was necessary since the present exterior finish was stopping the house from "breathing", leading to damp problems inside the building.

[13] Part of the site is the farmyard, which has displays of traditional agricultural equipment, brought together by the Trust and the Craigavon Historical Society, as well as a forge and a dairy.

The property is notable for its furniture collection, as well as the 18th-century Dutch, Flemish and Italian paintings on display, acquired through gifts and loans.

[17][18][note 2] In 2005 the National Trust purchased a Māori taiaha and an adze from Mangaia that had been acquired by George Ensor III during his travels in the Pacific.

[20][21] Notable pieces of furniture in the house include an Irish Chippendale sideboard, and a mahogany bureau that doubles as a bookcase which was created around 1725.

[6][22] Part of the collection includes the table on which the constitution of Northern Ireland was signed on 22 June 1921 by George V.[23] Artists represented by works listed as part of the collection at Ardress House include: Strickland Lowry, Gillis Neyts, Robert Griffier, Pieter Boel, Bartolomeo Passarotti and James Barry.