Concor’s Ikusasa building benchmarks top-level green rating

The Ikusasa building in Rosebank.

Concor’s Ikusasa building in the Oxford Parks precinct in Rosebank, will be the first of its projects to achieve a Green Building Council of South Africa’s (GBCSA) 6-Star Green Star SA Office v1.1 design certification, an internationally recognised mark of quality for the design, construction, and operations of buildings, interior fit-outs, and precincts.

According to Concor contract Manager, Martin Muller, the company has constructed a number of buildings in the development (and elsewhere) to 5-Star Green Star SA level:

Concor’s strict performance strategies to manage water use, energy consumption, process waste, and pollution all contribute to upholding critical environmental standards. In addition to carefully applying our client’s sustainable designs, our quality systems all contribute to the points requirement in the GBCSA rating.”

These include Concor’s application of a comprehensive Environmental Management Plan on site, in line with its ISO14001 accreditation. It also applied a rigorous Waste Management Plan, which saw 70% of demolition and construction waste being re-used or recycled rather than going to landfill.

We also conducted a hazardous materials survey on the project site before demolishing existing buildings, in accordance with the Occupational Health and Safety Act and other legislation,” he says. “Wherever we found asbestos, lead or polychlorinated biphenyls, these substances were responsibly removed as the law required.”

Annelide Sherratt, head of the department for green building certifications at Solid Green Consulting, notes that four key members of Concor’s site team completed the Green Star online course – which helps the team understand and apply sustainable ratings on the project. Sherratt highlights that the Green Star certification focuses on nine categories of sustainability achievement, from management and materials to the reduction of energy use, water, and emissions.

In terms of the materials category, for instance, the Green Star rating rewards developers and contractors for reducing the number of natural resources used, and for reusing materials wherever possible,” she says. “At the Ikusasa project, Concor reduced the portion of ordinary Portland cement used in their concrete mixes by 30% as an average across all concrete mixes used in the project and achieved a level of 60% recycled content in the steel requirement.”

Local sourcing of materials also played a role in this category, where Concor sourced 20% of the contract value from suppliers within a 400 km radius of the site, and 10% within 50 km.

In terms of energy efficiency, Ikusasa aims to achieve a Green Star SA Net Zero Carbon Level 1 – by generating as much energy on site as the base building would require, including the use of a photovoltaic (PV) solar generation system on the roof of the building, producing renewable power. The building’s design and operation enhance energy efficiency by applying sub-metering to track and control the main areas of consumption.

Any energy uses of 100 kVA or more are metered separately so users can benchmark usage targets and implement opportunities to reduce consumption,” she says. “This impacts on the production of greenhouse gasses and other emissions associated with electricity generated by fossil fuels.”

The data generated by the metering system is captured and analysed by a digital monitoring system for building management, but it is also shared with the building’s tenants and visitors on a public display screen – aimed at raising awareness and driving energy-efficient behaviour.

Conserving water is another important element of the building’s environmental performance. This is optimised using options like low flow tap fittings and dual flush toilets, as well as water sub-metering for uses such as irrigation and bathrooms. Plant irrigation was reduced by 50% using water-wise irrigation methods and smart sensors. In addition, the heating, ventilation and cooling system is cooled by air rather than by water.