[1] Horningsea Park was one of Governor Lachlan Macquarie's large pastoral grants made following the establishment of Liverpool in the 1810s.

Horningsea Park was part of an integrated area of large pastoral grants (mainly to military or civil officers or wealthy free settlers) which stretched from Liverpool to the Nepean River.

[2] There were five employees listed as working on the property in the 1828 census: a woman servant, a boot maker, a gardener and two labourers.

The cellars were filled in, the (front) verandah was replaced with the present porch, the eastern part of the house was reconstructed, and some outbuildings were demolished.

[3] Following the loss of its pastoral context in the 1950s, by 1960 the holding was reduced to 22 acres (9 hectares), the size and shape it remains today.

[1] The house was classified by the National Trust of Australia in 1976, when it was also saved from demolition after intervention from the Minister for Planning and Liverpool Council.

[1] The house was stabilised, progressively reconstructed (from 1982) and what was the gutted shell was extensively renovated following its recognition as a heritage item and making of a permanent conservation order in 1983.

[1] At that time some of the outbuildings were still standing and the work included demolition of a single-storey service wing on the northern side of the house.

[1][8] Horningsea Park is a two-storey brick/rubble and stucco Georgian style house set in the remains of its former estate, still retaining the long entrance driveway from the Hume Highway.

[1] The intact survival of Horningsea Park for so long as a large rural entity is significant testimony to its viability as a pastoral and dairying assemblage.

In relation to its setting within the estate, the house retains an ability to demonstrate socially and historically significant concepts about Australian colonial and post-colonial life.

A fine early Georgian homestead, with visual evidence of its former estate and surrounded by trees some of which are from the original garden.