Infrastructure and buildings services company Concor has completed the Ikusasa office block in Rosebank’s Oxford Parks precinct to six-star Green Star South Africa Office green standards, with 70% of demolition and construction waste re-used or recycled, Portland cement use reduced by 30% and 60% recycled content used for the steel requirements.

The company has built several buildings, in this development and elsewhere, to five-star Green Star South Africa levels in terms of the Green Buildings Council South Africa (GBCSA) certification.

Ikusasa will be the first project to achieve a six-star Green Star South Africa Office design certification, says Concor contract manager Martin Muller.

“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,” he says.

These included Concor’s application of a comprehensive environmental management plan on site, in line with its ISO 14001 accreditation.

“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. Wherever we found asbestos, lead or polychlorinated biphenyls, these substances were responsibly removed, as the law requires,” he points out.

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. The heating, ventilation and cooling system is also cooled by air rather than by water, says Muller.

Further, Ikusasa aims to achieve a Green Star South Africa Net-Zero Carbon Level 1 score, by generating as much energy on site as the base building would require, and includes the use of a solar photovoltaic generation system on the roof of the building, producing renewable power.

“The building’s design and operation enhances 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.

"This impacts on the production of greenhouse gases and other emissions associated with electricity generated by fossil fuels,” says green standards services company Solid Green Consulting green building certifications department head Annelide Sherratt.

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 example, the Green Star rating rewards developers and contractors for reducing the amount of natural resources used, and for reusing materials wherever possible,” she says.

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.

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