The firm currently operates an 87,000 sq ft head office at Maple Avenue as well as a warehouse and a saleroom in the city.
The auction house will move to the new 160,000 sq ft location in Dallas later this summer.
Heritage spokesperson Eric Bradley said: “For security reasons, we cannot disclose the address or location of the new facility just yet except to say that it is in Dallas.
“This is the most significant expansion in the firm’s history and a consolidation such as this sets the stage for Heritage to grow and increase communication between all departments. Bringing everyone together makes logistical sense.”