The pair of houses at Nos 86-88 Windmill Street, part of a larger group built by the Musgrave family, is of State significance as a rare surviving example of a modest group containing a shop and residences dating from the late 1850s, and are an integral part of the Millers Point and Dawes Point Village Precinct Conservation Area.

This pair of houses forms part of a group of buildings constructed in stages by the Musgrave family from c. 1856 until 1861, containing their business premises (No.

As individual buildings, they are highly significant as rare surviving examples of the modest Colonial Georgian houses, demonstrating the effect of the Sydney and London Building Acts which sought to control the spread of fire by controlling the materials and design of town houses in tight urban environments.

The surviving cast-iron work is a typical early nineteenth-century pattern, which can still be found in London and elsewhere in Millers Point.

The housing in the block between Argyle Place and Windmill Street is of a higher density than most of the other surviving early townscapes.

The pair of houses is an excellent indication of the standard of buildings retained by the Sydney Harbour Trust following the resumption of the area in the early twentieth century.

[1] 86–88 Windmill Street, Millers Point was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria.

Evidence of the small commercial area that developed at the eastern end of Windmill Street, containing shops and public houses which catered to the local residents, sailors and ferrygoers.

[1] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

[1] The place has potential to yield information that will contribute to an understanding of the cultural or natural history of New South Wales.

[1] The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales.

A building form once common throughout Sydney by 1850, this group of late Georgian style terrace houses are among the very few to survive; the main concentration of the type are within the area resumed in 1900.