[2] Strickland House's site has been identified as having twelve phases of historical development[1][3]: 7  from the pre-European occupation of the site; to the first grants made to William Wentworth, who gifted this part of his estate to his daughter, Thomasina, and her husband, Thomas Fisher, in the 1830s–55 (they did not build on it, returning to England); to Charles Lowe, who may have started building the house, but then on-sold the site; to John Hosking, Sydney's second mayor (who owned it 1855–76) who built Carrara and lived here; to Henry Moore and his family (1876–88); to Arthur Wigram Allen, tenants and caretakers (1888–1899); Tudor House (1899–1902); to other members of the Allen family (1902–14); and then through a period of ownership and use by the NSW Government / Minister for Lands (1914–15) who bought the site with funds from the Foreshores Resumption Scheme for use as a 'public recreation ground'; for subsequent re-purpose as the Strickland Convalescent Home for Women (1915–33); and then as a Convalescent Hospital for Men and Women (1933–60); and as the Strickland House Hospital for the Aged (1960–90); and finally in its current phase of ownership and use since 1990.

Ample accommodation, excellence of designs, and substantial workmanship, combine to produce a home replete with all that is essential to comfort, convenience, and respectability.Henry Moore (1815–1888) moved into Strickland House in 1879 with his wife, Elizabeth, and seven of his adult children.

The grounds, now much curtailed, were then rich with beautiful trees and shrubs, with grass in front sloping down to a white sandy beach where there were dressing sheds and an enclosure for bathing.

Woollahra History & Heritage Society (WHHS) president, Peter Poland, and his (late) wife, June, campaigned to preserve Strickland House and its grounds in community use for more than 22 years.

[1] A Strickland House Advisory Committee was established by then Planning Minister, Robert Webster, in January 1993 to call for, examine and recommend proposals for the property's future.

Premier Carr in August 1997 launched the Government's "Vision for Sydney Harbour", which included maximum public access to and use of foreshore land, and protection of all items of heritage significance.

[1][22]: 18  At an annual open day in 2002 the WHHS noted a record attendance and people from over 150 Sydney suburbs and many places elsewhere, who signed a petition and letters to then Premier Carr.

[1][22]: 19  At an annual open day in 2004 a new record of people from over 162 suburbs of Sydney and other places visited the site and signed petition and letters to Premier Carr seeking retention in public ownership, no sale or long-term lease and control on development, subdivision and refurbishment of the house.

Conservation works to the exterior of the house have since been undertaken, including removal of the fire escape stairs and glass verandah infill on the west and south facades.

[1][3]: 21 The State Planning Authority sought private sector interest in rezoning parts of the site for residential or commercial use, including options of low-density housing, small business spaces and a function centre.

[23][1] At an August 2012 Community Cabinet meeting, the Society requested Minister for Heritage, Robyn Parker consider gazetting the Strickland House land as a Public Park.

[25][1] On an open day on 3 May 2015 Gabrielle Upton MP unveiled a special memorial seat honouring the life and contribution to heritage of June Poland OAM (1935-2013).

The forested backdrop of scattered native trees on the high land to the east of the site is thought to be an intended original "picturesque" feature of the landscaping and is still retained.

[34][1] Strickland House is a Victorian Italianate mansion virtually intact and consists of three storeys of sandstone, which was unusually painted, and features verandahs with Doric columns.

[1] As at 16 February 2004, The Strickland House site on Sydney Harbour, Vaucluse, is of exceptional historical significance as a remarkably intact 1850s villa with a largely unaltered landscape setting.

[35]: 99  The intact nature of the original residence and its landscape setting, including the strong relationship that remains between the house and the water, are rare in the context of metropolitan Sydney.

The site's associations with the historical figures of William Charles Wentworth, the original owner of the property, John Hosking, who substantially developed the grounds of Carrara, and subsequent occupants including Henry Moore and members of the Allen family are also of significance.

[1] The garden and grounds of Strickland house are of cultural significance on a state level for their siting and development, largely credited to the Hosking period of ownership, according to romantic picturesque principles.

Strickland House was placed to take advantage of the ideal romantic site on Sydney Harbour with the vegetated area between the carriage drive and Vaucluse Road functioning as a backdrop.

"The land, gardens, buildings and other works contained within Carrara/Strickland House demonstrate an evolving landscape of over one hundred and forty years, reflecting popular and personal tastes and fashions as well as institutional philosophies of patient care and wellbeing.

The mixed planting of evergreen and deciduous trees and shrubs together with the topographic variety, the vistas and views, the features such as walls, terraces and paths have produced a landscape with a strong design quality and character which is in stark contrast [to] the subdivided areas surrounding it.

The idiosyncratic features of the Stables building, including projecting sandstone blocks, quoins at one corner only and gable end finished in brick masonry, have an eccentric aesthetic appeal.

The entire area to the south west of the Northern Dormitory (Block A) has been modified to form a large open space affording panoramic views over Sydney Harbour.

Contemporary community esteem is further demonstrated by ht inclusion of the property on various heritage registers, being considered one of the finest houses in Sydney from its inception, has retained the landmark status that was recognised from its mid nineteenth century establishment.

"The high degree of integrity of both the main house interior and exterior as well as that of the garden make Carrara a valuable research tool and example of taste and style particularly during the nineteenth century.

Regardless, potential archaeology at the Strickland House site may be related to the following research areas:[1] "The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales."

The high integrity of the land immediately surrounding the house offers a rare opportunity for the appreciation of a picturesque aesthetic as designed in the mid nineteenth century.

Carrara is a rare surviving example of an early Victorian mansion of substantial scale retaining not only its spacious landscaped grounds, but also its near original relationship to the harbour.

[35] Carrara is an exceptionally intact and excellent example of John F Hilly's work that contains a distinctive two storey bow front veranda not common to residences designed at that time.

Although relatively plainly finished on the exterior, the Stables building contains some very unusual features, notably: The specimen of tuckeroo (Cupaniopsis anacardioides) located at the top of the slope in the vicinity of Strickland House has some scientific value as an indicator of the natural littoral rainforest vegetation of the site.