South African construction major, Concor was appointed as the principal contractor on the Public Investment Corporation (PIC)’s Trevenna basement project in Sunnyside, Pretoria. The basement project is a precursor for A-grade office buildings in the Trevenna Office campus.


According to Martin Muller, Senior Contracts Director at Concor, the contract is part of a multi-phase development at the Trevenna Campus and started shortly after the major earthworks were completed. Concor will carry out the first and second phases of the project, which comprise the five-level, 68,000 square metre super basement – with all services, lobbies and finishes. The basement extends some 20 metres below ground level, and will be constructed with post-tensioned concrete slabs.


“This large basement extends some 20 metres below ground level, and will be constructed with post-tensioned concrete slabs,” says Muller. “The scope of work also includes extensive underground services such as sewer and stormwater infrastructure, electrical reticulation, lifts to the ground floor and access control.”


Phase 1 of this 11-month project began in February 2022 and was followed by Phase 2, which started in March. The third phase, which is yet to be awarded, will comprise four A-grade office buildings some five storeys high, making up almost 43,000 square metres to be constructed above the super-basement.


In line with the local procurement principles, the project will rely heavily on local subcontractors, suppliers and labour, with a considerable workforce of 500 to 600 people active on site. Among the key subcontractors are specialists in excavation, formwork, concrete, post-tensioning and reinforcing.


Muller explains that Concor deployed four tower cranes on the site to facilitate the fast pace of construction required, ensuring the safe and expedited movement of steelwork, formwork and other construction materials. Space is at a premium, as the footprint of the basement extends across almost the entire site. “This necessitated the pumping of readymix concrete in-situ for the post-tensioned slabs,” he says, noting that dealing with the challenges of congested urban environments is one of Concor’s many strengths.


“This is the first contract that we are undertaking for the PIC, and we look forward to delivering excellence and demonstrating our extensive capabilities,” says Muller.


Concor is currently building a super-basement as the first phase of the Trevenna Office Campus.

The basement is 20 metres below ground covers 68 000m² over five levels.

Readymix concrete is pumped for the in-situ construction of post-tension slabs.