Once home to the Clutha County Council, the building had been largely unoccupied for more than a decade.
It had no formal historic classification or protection.
Demolition crews have spent the past fortnight gutting it and the building behind, Berriedale House, both sites owned by Balclutha businessman Blair Cross.
Yesterday, they turned their attention to knocking the buildings down, attracting a steady stream of onlookers.
It is not known what plans Mr Cross has for the vacant central site.