Constructed in 1896 in St. John's by the contractor William Ellis, the Commercial Chambers Building located at 199 Water Street is a fine and well maintained example of post-fire architecture. William Ellis established his business in 1890, and was one of the most important reconstruction contractors in St. John's after the Great Fire of 9 July 1892. By the early 1900s Ellis was one of the city's largest employers. In addition to the Commercial Chambers Building, his most significant projects were the main tunnel of the St. John's sewage system, the St. John's Total Abstinence and Benefit Society Hall, and "Merchant's Block" on Water Street. Ellis served as Member of the House of Assembly for Ferryland from 1904-1909, as Mayor of St. John's from 1910-14, and as Minister without Portfolio from 1918-1919.

The Commercial Chambers Building was primarily occupied by various merchants and insurance companies. The ground floor was devoted to mercantile and specialty operations in the early twentieth century, the inheritors of nineteenth-century fish exporting merchant traditions. Most notable were the firms of R. H. Trapnell, the Ewings, and Robert A. Brehm, who began to manufacture margarine in Newfoundland in 1883. The office space, located above, was occupied by William Ellis, the American Consulate, the lawyer and politician Sam Foote and T.B. Clift Limited.

A three-storey Victorian structure, with five bays and a stained glass window, the Commercial Chambers forms an important and instantly recognizable contribution to the downtown cityscape. The powerful effect of the rose granite columns, set against the more passive grey of the dressing stone, lends a sense of permanence and authority to the commercial premises on the streetscape. The interior of the building is characterized by a sky lit, open stairwell. The Commercial Building is a former recipient of the St. John's Heritage Foundation Award, the first commercial property to be so honoured. In 1996 the Commercial Chambers Building was designated a Registered Provincial Heritage Structure by the Heritage Foundation of Newfoundland and Labrador, and a grant was provided to assist with the restoration. It has been restored by Geoff Hiscock, whose care for architectural and stylistic consideration have allowed the building to survive as one of the great downtown commercial premises.