The Woolshed at Mount William Homestead is a large bluestonebuilding erected for pastoralist brothers Thomas and Andrew Chirnside in 1865.
Constructed in coursed masonry, the structure has a large, flat, hipped slate roof. There is a pyramid roofed, weatherboard tower and weatherboard extensions. Some openings in the main structure are slatted vents and others are glazed. Roof lights have been added.
The very large woolshed is notable for its size and as a representative example of a substantial woolshed erected on the large partoral station during this era. The structure illustrates the scale of operations of such stations and the wealth that was associated with them, particularly as exemplified by the Chirnside brothers, who held Mount William from 1842. Stylistically the structure is Colonial vernacular.
The woolshed is understood to be essentially intact and is in good condition, although some deterioration of the roof has occurred.