ISG, which is leading the project to transform the former BHS store into a £20 million mixed-use development, hailed the step as a key milestone.
The contractor has systematically demolished the existing property over the last 15 months to allow for the erection of the new hybrid concrete and steel frame building that can now be seen on the Edinburgh skyline.
The project, due to complete next summer, includes two new restaurants on Rose Street and a flagship 40,000 square foot retail outlet on Princes Street.
ISG regional director in Scotland Paul Beaton said: “This has taken an enormous effort by our project team and, given the complexities of the site, it has required meticulous planning to reach this point.
“This milestone signifies the next step in rejuvenating this underused space, providing exceptional new hospitality, retail and dining facilities in the heart of Edinburgh.”
Steve Spray, fund manager at LaSalle Investment Management, which represents the owner of 64 Princes Street, added: “This is an important redevelopment for Princes Street, bringing vital city centre floor space back into commercial use and this is a big step in realising that vision.”