For instance, says Patrick McInerney, director of Co-Arc International Architects, it is the first time that a skyscraper of this magnitude is fully designed by a South African company - previously the lead architects for such big buildings were always foreign firms, which contracted out some of the work to local companies.
Co-Arc International Architects have worked on The Leonardo for more than six years, starting from a few tentative sketches on paper.
Currently, the building stands at 210m but will be 233m tall when construction is finished, with completion scheduled for sometime in the second quarter.
The second-tallest building on the continent is the Carlton Centre in Joburg, which was built in the 1970s.
Africa’s tallest skyscraper will have absorbed more than 8.7million kilograms of steel by completion, McInerney said in a telephonic interview.
That’s more metal than in the Eiffel tower, but you won’t see it as the concrete and masonry structure is what is exposed.
The Leonardo was also deliberately designed to be labour intensive.
By the time it reaches completion, it will have taken millions of man-hours by teams involved with everything from bricks and mortar through the design of air-conditioning systems to calculating the impact that high winds could have on the structure during a highveld storm.
About 18000 to 20000 jobs were created throughout the project.
“We started when all that was left by a previous project on the site was a big hole.
"We built The Leonardo by working in-between the foundations of the previously failed building,” he said.
That meant The Leonardo would ultimately be quite a “thin” building.
The Leonardo also continues the architectural firm's association with South Africa’s “richest square mile”, which began in the 1980s with the design of the Nelson Mandela Square for the city council and the Michelangelo Hotel for the Legacy Group.
The Leonardo is also being developed by the Legacy hotel group.
Also, because the skyscraper was built immediately after a global recession, it was designed so that it would be financially viable at a variety of heights.
As each construction milestone was reached, and as sales targets were achieved, the design was adapted to suit the requirements of the next stage, added McInerney.
“The new tower will be completely integrated into the neighbourhood, providing a new residential and lifestyle offering within the CBD and transforming Maude Street in Sandton from that of a financial centre to a lifestyle destination,” he said.
The 55-storey building is mixed use, with retail and commercial businesses and offices on the lower floors, while the upper levels will comprise apartments and a hotel.
There will also be a public viewing deck on top.
Unlike most of its neighbours, The Leonardo is a publicly accessible building.
“Having the option to live, work and play without leaving the precincts of the CBD provides a balance to an urban life yet to be experienced in Joburg,” said McInerney.