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The Leonardo by RMCE for Legacy Group, Sandton, Gauteng
COMMENDATION The Leonardo by RMCE for Legacy Group, Sandton, Gauteng
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The 56-storey Leonardo building was completed in 2020 and at 234 m tall is now Johannesburg’s and Africa’s tallest skyscraper, comprising retail, office, residential and hotel accommodation. This is a R2 billion investment in Sandton, the hub of the African economy.
Since the early 1990s, The Legacy Group, financed by Nedbank, has developed six notable mixed-use buildings within Africa’s richest square kilometre, including Nelson Mandela Square, The Michelangelo Hotel, DaVinci Hotel and Raphael penthouse suites, the 34-storey Michelangelo Towers and, lately, the Leonardo complex located at 75 Maude Street, Sandton. All these impressive buildings have been engineered by Ritchie Midgley Consulting Engineers, in collaboration with the developer’s team of architects, quantity surveyors, MEP and related services engineers and project manager.
The Leonardo broke ground in an existing basement excavation on 17 November 2015. Four basement levels of prestressed flat slab parking top out at ground level. A podium, rising seven storeys above Maude Street incorporates additional parking, retail stores, a reception area, conference halls, restaurants, health spa and gym, pool, terrace with a bar service, as well as a Montessori school for the convenience of office workers and residents of the building.
There are 1 300 parking bays, 7 200 m2 office accommodation, 232 apartments and duplex units, eight penthouses, the 1 900 m2 Leonardo Suite and a hotel. The iconic architectural design of the building is complemented by more than 800 original art pieces showcasing emerging and established South African artists. Towering 44 storeys above the podiumlevel pool deck, the northern façade columns located on a mid-column grid terminate on to an 11 m high ‘keyhole wall’ that transfers the superstructure loads on to the regular column grid below. This feature has enabled the architect to have column-free floor space surrounding the central core, which is suited to different spatial requirements for offices, residential accommodation, and the hotel. This feature increases sustainability of the building since future occupancy remodelling is ensured.
A feature of this building are out-rigger walls cantilevering off the main shaft, connecting the perimeter columns to the stiffer core structure. These structures accommodate both the compression and tension load effects from wind-induced deflection, thereby stiffening the structure to achieve a plumb lift core and sway that is limited to well below conventional design limits.
The tower block was constructed over a seven-day cycle per floor, lagging the lift core by three floors. During the 42 months of construction, 56 000 m3 of concrete was cast at an average of 45 m3 per day, limited mostly to nighttime pours to alleviate traffic congestion.
The core topped out on 9 April 2019 followed by the top-most viewing deck slab on 25 May 2019, and a Certificate of Completion was issued on 26 July 2019.
PROJECT TEAM
Client: Legacy Group Holdings Architect: Co-Arc International
Consulting Engineer:
Quantity Surveyor:
SM Schneid Quantity Surveyors Façade Engineer: Arup
