It was added to the Queensland Heritage Register on 27 October 2000, and is considered significant for its aesthetic contribution to the streetscape of Margaret Street, for its status as surviving evidence of the early development of the commercial centre of Toowoomba, and for its association with Marks.

[2] The Exchange Building is a two storeyed row of 4 brick shops, constructed by at least July 1905 to a design by prominent Toowoomba architectural firm, J Marks and Son.

The site now known as Toowoomba was eventually considered to be in a more suitable location for access down the range and in 1852, a town survey was secured.

The establishment of a new town was strongly supported by the squatters and Toowoomba challenged Brisbane as the new capital of Queensland.

[1] As Toowoomba developed a commercial centre emerged in the blocks bounded by Russell, Ruthven and Margaret Streets and the construction of a police station and post office near the Toowoomba Court House (1877) firmly established the upper end of Margaret Street as a government precinct.

James had commenced practice as an architect in Toowoomba by the early 1880s, and he and Harry have been described as dominating the architectural profession for more than half a century.

Although Harry Marks was responsible for designing a number of buildings on both the Darling Downs and in Brisbane, much of his work was in Toowoomba where he designed a variety of buildings including Rodway, St James Parish Hall, and St Luke's Church Hall, additions to the Toowoomba Maltings, and the Darling Downs Co-operative Bacon Factory.

Marks was also described as being gifted with inventive genius, and he devised and patented a number of architectural elements, including roof ventilators, windows and a method of stucco wall construction.

Following a distinguished military career, Robertson returned to Toowoomba where he set up a very successful stockbroking business.

At this time those listed at 249 Margaret Street are Hertzberg & Co (AM) Merchants; Downs Mercantile Finance Company Ltd; JC Robertson; Ocean Acct Corporate Ltd and GP Jackson, a jeweller and ironmonger.

The pattern of the paired windows, the pediments and interplay between the red brickwork and rendered architectural detailing results in a pleasing and economical composition for a commercial building.

Erected in the period at the turn of the century when Russell, Ruthven and Margaret Streets were being consolidated as the commercial centre of Toowoomba.

The building has a decorative rhythmic facade which makes is a substantial aesthetic contribution to the streetscape of Margaret Street.

It is one of a number of extant commercial buildings designed by the Mark's family that contribute to the architectural character of Toowoomba.