Concor has completed the tallest residential block in Cape Town’s city area – fronted by a carefully preserved, century-old façade onto one of the trendiest streets in town.
16 on Bree is remarkable not just for its size but it transforms an old two-storey block into a modern 38-floor luxury development. According to Concor Western Cape senior contracts manager Collin Morilly, an early challenge was the preservation of the fragile heritage façade.
“The 16-metre-high wall was not built out of concrete but of rock, clay and lime and it required very gentle treatment and firm support. We erected a specially designed structural steel brace that would support the wall and prevent any structural failure while it was cut free from the rest of the building which had to be demolished”.
A concrete beam was also cast along the base of the façade to act as a counterweight and to prevent any movement. As the new structure was built, it was stitched in with the braced façade until the brace could be removed. There were also three other heritage walls within the building, standing in a U-shape, which were preserved during the construction process.
“The project also had to be implemented in the highly space constrained city centre, with busy roads on all boundaries of the site. This meant there was almost no laydown area for materials and equipment, and we had to ensure an uninterrupted flow of vehicular and pedestrian traffic” he says.
This was a significant achievement for Concor given the scale of the project which consumed 21 000m3 of concrete, 1 650 tonnes of reinforcing bar and 650 000 bricks. The new height of the building required the placement of 40 concrete foundation piles. Tower cranes had to be carefully managed to lift and to place materials, a task made more difficult by the high winds for which Cape Town is known, especially in summer.
“Then came the unexpected disruption of work due to Covid-19. We were soon able to get back to work after the initial lockdown, but this required extra vigilance and discipline because of the number of workers in such a confined space”.
With approximately 900 people on a relatively small footprint over multiple floors meant that Covid-19 protocols had to be strictly implemented, based on a thorough understanding by all employees and subcontractors of the infection risks.
“Social distancing was a particularly onerous aspect for us to adhere to, as the nature of construction demands that workers operate in teams and groups,” he says. “For example, a team of tilers must work in an apartment together, but the regulated social distance must be observed. This required that fewer workers be allowed into an area, which reduced overall productivity.”
Drawing on the expertise of its trusted subcontractors, Concor’s experienced supervisors kept a close eye on the pace and quality of work, with at least four foremen looking after each floor.
“We run our projects according to our SANS 10400 and ISO 9001 accreditation, and this means close management of the quality assurance and quality control process,” says Morilly. “Our systems included the SnagR snagging software to accurately record and close out snags timeously, and the Synergy document control software to facilitate timeous issue of information, tracking and recording.”
The Finishes Matrices system was also employed, indicating the level and the apartment in which each of the trades should be working every day.
The result has been an elegant structure gracing Cape Town’s city skyline, rising 120 metres from street level and comprising 380 upmarket apartments. The future may hold scope for further residential units, making use of space currently used for the parking areas. To make this possible, the parking floor-to-ceiling heights were designed to the same dimensions – 2,9 metres – as the apartment levels.