This spectacular rococo plasterwork was the work of James Byrne, who in1765 was paid just over £446 for plasterwork in the house. Brownlow was indeed pleased with the work and Byrne received £7 as a present for doing his work well.

The front ground floor room at No. 12 was quite possibly the original dining room. The walls have large perfectly moulded plaster panels which are undoubtedly related to a group of Irish Interiors inspired by French rococo boiseries.

The splendour of Sir Brownlow's new house in Dublin reflected his status in Dublin society and fitted the increasing needs of his advancing political career. In 1776 a short time before the house was completed he was sworn into the Privy Council. It is not surprising that Brownlow opted for a French-inspired interior. Not only was rococo very much in vogue at that time, he also had some connections with France. He lived in France for some time as a child and later on as an adult he revisited the country on several occasions.

Brownlow's will, proved in 1794, displays a sobriety and restraint quite at odds with opulent interior of his Dublin house.

He made request that he be "decently buried privately and without any ostentation or superfluous expanse either in the parish where I shall die or in such other convenient place as my executors shall appoint, it being to me a matter of the utmost indifference".