The World Wide Fund for Nature-South Africa (WWF-SA) will next month officially launch its new green premises, on the corner of Melle and De Korte streets, in Braamfontein, Johannesburg, following the conclusion of the 14-month- long refurbishment of an existing building in January.

WWF-SA business development and fundraising head Andrew Baxter tells Engineering News that the project has culminated in significant reductions in energy and water consumption. A significant portion of the previous building’s materials is being reused for the WWF-SA’s new head office.

Construction project management services provider Bornman & Associates director Richard Duckitt, who is also the building sustainability consultant for the brownfield project, notes that more than 80% of the waste stream created by the project was diverted from municipal landfill and recycled through a variety of initiatives, including on-site reuse and donations to charitable organisations.

“Except for the façade, the original building was deconstructed brick by brick. These bricks were all used in the construction of the new building,” he asserts.

Baxter adds that the pressed-steel ceiling fixtures and wooden roof rafters of the original building were also reused, while some of the wood is being recycled into office furniture.

Further, all the building material and equipment used were meticulously assessed for their life-cycle carbon footprint and environmental impact – only material and equipment with the lowest impact were reused. “We worked closely with all the suppliers to ensure that only the greenest solutions were used for the construction of the building,” says Baxter.

The building also employs several technologies to reduce operating energy, such as the use of light-emitting diodes (LEDs) and energy efficient T5 fluorescent lighting, which are linked to occupancy and daylight sensors. The lights are dimmed or switched off if sufficient natural daylight is available in the office space.

The façade of the WWF-SA’s new head- quarters has double-glazed glass in the windows, which significantly improves the building’s thermal insulation and, consequently, energy demand in terms of heating the building. The windows also reduce the ambient noise from the Johannesburg streets.

All perimeter windows of the building are fitted with automated blinds, which control the amount of direct sunlight penetrating into the workspace, reducing the glare on computer screens and thermal heat gain. “Together with this intelligent lighting system, energy consumption is reduced by maintaining a balance between natural and artificial light,” highlights Duckitt.

To limit the building’s water use, a black water treatment plant was installed in the basement. Black water refers to wastewater generated from sewage, while grey water refers to wastewater generated from handwash basins and showers.

Duckitt explains that the plant treats and recycles all effluent produced in the building, which is reused for toilets and landscape irrigation: “No sewage water is discharged into the municipal sewerage system. The effluent is circulated through an anaerobic digestion process, which breaks down the waste material and significantly improves the quality of the water. It is a closed-loop system and every litre of water used to flush a toilet is recycled into the building.”

However, while the treatment process improves the quality of the water, it is not fit for human consumption, he adds.

Baxter highlights that only the potable water demand is met by municipal water infrastructure.

On the roof of the building, a rainwater harvesting system – connected to an 8 000 ℓ storage system in the basement – further supplements nonpotable water demand.

Duckitt notes that the system was designed with slabs to reduce the outflow rate of stormwater and to ensure that water is captured. Once captured, the water is filtered and cleaned in the treatment plant for use in the building.

If storage capacity is reached during a storm, the system is also designed to slow the rate at which it discharges the water into the urban stormwater infrastructure, reducing the potential impact of exceeding the capacity of the stormwater drainage system in the area.

Meanwhile, Duckitt points out that an important aspect in selecting the site was the proximity of the building to public transport infrastructure to promote commuter behaviour among WWF-SA employees, as this reduces the carbon emissions of single-user vehicle commuting.

Cycling facilities have been designed for the building to promote this type of commuting to work. The facilities include designated and secured areas for bicycles, lockers for cyclists to store their equipment and showers for workers to use before going to work.

Duckitt points out that the dedicated cycling lanes built by the City of Johannesburg, as well as the Johannesburg Development Agency’s February announcement of a R120-million investment into the development of a connecting cycling lane from Park Station to the University of Johannesburg, will further promote the use of alternative modes of transport.