The land Hestock stands on was originally part of the Passy Estate, a landholding of considerable extent stretching from what is now Woolwich Road to Alexandra Bay between Ferry and Crescent Streets. Between 1855 and 1857 Passy, a substantial stone villa, was built for Monsieur Louis Sentis the French Conul at the time. Sentis sold shortly afterward to Edye Manning. Hestock was built in 1885 by Alfred Christian Garrick the owner of Passy. The architect was Walter Liberty Vernon, later the New South Wales Government Architect from 1890 to 1911. Vernon also designed the Hunters Hill Post Office. The house was illustrated in the "Australian Builder's and Contractor's News" of 18 August 1888. In 1886 John Arthur was the tenant of the house and H. B. Cotton from 1888. The house was named Le Chalet during (at least) the years 1890 to 1924. There is anecdotal evidence to suggest that it was known as Le Chalet up until 1968. According to anecdotal evidence, the service wing originally featured a timber verandah (now demolished) which had a laundry with a bricked in copper and, later, a gas copper and cement wash tubs. Adjacent to this was a wood shed and a toilet. Before the subdivision of land on the Western boundary, there were two garages and two workmen's sheds as well as a corrugated iron work water tank. The house itself has the words "Hestock AD 1881" carved into a dressed stone quoin adjacent to the entry porch. As Walter Libery Vernon sold his architectural practise in Britain and came to Australia in 1883 the date on the house cannot be correct (as Vernon was not in Australia at that time). The house must have been constructed between 1883 (the time of Vernon's arrival in NSW) and 1888 (the years it was illustrated in the Builder's and Contractor's News). As it was occupied in 1886 it does appear that an 1885 construction date appears likely. Hestock was nominated for a Permanent Conservation Order in 1979 by the then owner Mr Evans. The Permanent Conservation Order was gazetted on 27 June 1980. It was transferred to the State Heritage Register on 2 April 1999. Hestock is a substantial two-storey sandstone residence, with verandahs on three sides. The sandstone walls are rock-faced ashlar and feature smooth dressed quoins and smooth dressed stone mullions to the windows. The house is asymmetrical, with a steeply pitched gabled slate roof.