The area was farmed by convict labour during the penal settlement of the 1820s and 1830s, and in the 1840s and 1850s was sparsely settled with cottages erected on the higher land.

In the busy post-Separation decades of the 1860s and 1870s, an ad hoc process of land filling was undertaken as Frog's Hollow became more densely populated by the working classes, and shophouses, house-workshops, small factories or workshops, boarding houses and hotels were erected.

During the boom years of the 1880s, these residences and small workshops were replaced gradually with large and imposing commercial and industrial premises, as Frog's Hollow, conveniently located near the wharves, emerged as Brisbane's principal light-industrial and warehousing precinct.

By the late 1880s, engineering and ironfounding firms were particularly prominent in the lower Edward, Alice and Margaret Streets precinct, and included Smellie & Co., Smith, Forrester & Co., Harvey Sargeant & Co., and Overend & Co. Watson Brothers incorporated a small workshop at the rear of their 1887 warehouse, which was appropriately located in the metal-working precinct of Frog's Hollow.

Some of his better-known Brisbane residential work includes the alterations and additions to Fernberg (1888–90) at Paddington (now Government House); and Moorlands (1892) at Toowong.

He was also a successful businessman and property developer, took a keen interest in civic, church and benevolent affairs, served on numerous committees and boards, was a prominent freemason, and was a foundation vice-president of the Queensland Institute of Architects in 1889–90.

There were three rear doors on the second and third levels, and American lifts were installed to permit goods to be hoisted to or from the back yard.

[1] Despite serious flooding in 1893 and an economic depression in the 1890s, by the turn of the century Watson Brothers had emerged as Queensland's largest plumbing and sanitary engineering business.

The ground floor section of the two northern portions have been removed for vehicular access, but dividing walls remain extending to the rear of the building.

The pilasters to each side of the surviving southern ground floor portion are rendered to imitate stone coursework capped with mouldings and rosettes.

[1] The three portions are divided on the two upper levels by fluted giant order pilasters with ornate Corinthian capitals that include grotesque masks.

No trace remains of an earlier post-supported street awning (extant by c. 1902, but not part of the original design) with its curved corrugated iron roof and central archway.

[1] On the side wall facing the laneway it is still possible to distinguish signwriting describing Watson's goods - hardware and plumbing supplies.

The laneway provides a link across the city block and has a visual quality contributed to by the unrendered expanse of the side of the building.

These stone walls, of squared porphyry rubble laid in courses, are extended in height by two generations of brickwork additions which support the triangular timber trusses of the corrugated iron skillion roof.

Watson Brothers Building is important in illustrating the rise to prominence of local Queensland manufacturing and enterprise during the 1880s boom period, and demonstrates the evolution of Frog's Hollow as the principal warehousing and light-industrial sector of Brisbane's central business district during the second half of the 19th century.

The site includes a late 19th century yard and remnant evidence of the original stables and out-offices, and a workshop extant by c. 1918, the survival of which in Brisbane's central business district is a now rare aspect of Queensland's cultural heritage.

Watson Brothers Building is important in demonstrating the principal characteristics of an 1880s boom era warehouse with ornate detailing.

[1] The place has a special association with the life or work of a particular person, group or organisation of importance in Queensland's history.