Established with a purpose to inspire a built environment in which people and the planet thrive, the Green Building Council of Southern Africa (GBCSA) certifies green buildings. Water conservation plays an important role in its rating tools.“To date, the GBCSA have completed 905 certifications, and have certified 12.5 million m2 of buildings. This equates to an approximate annual saving 1 220 Mℓ of potable water,” explains Dash Coville, technical manager: Special Projects, GBCSA. Various tools can be used to certify buildings, and all of them have a water component to them. “Our suite of rating systems offers tools for almost any type of building. Certification creates a universal platform for credible and objective measurement of green buildings. Each tool recognises and rewards environmental leadership and is a recognised symbol of sustainability achievement,” states Dash. Green Star Rating Tools “It is important that both new buildings and existing buildings consider green building certification. A New Build rating is an asset rating, it is a once-off rating and is based on the design, and therefore predicted performance, of the building. However, the performance of a building must be evaluated. The Existing Building Performance Tool certifies actual performance of the building. This closes the loop, ensuring what is designed to be efficient is operated to achieve this efficiency,” adds Coville. The New Build rating tools validate the environmental initiatives of the design phase of new building construction or base building refurbishment or the construction and procurement phase of the new building. The Existing Building Performance tool validates the environmental initiatives of the operational phase of the building’s lifecycle. Furthermore, it provides a calculator which is used to predict the expected water savings. The New Build and Existing Building Performance Tools have different criteria but they evaluate water usage in three main areas: water consumption, water quality, and water management.
- Water consumption: Encourages buildings to minimise their water consumption by implementing measures such as installing water-efficient fixtures and fittings (low-flow showerheads and toilets), and designing buildings that use less water in their operations, such as those that recycle water or capture rainwater for reuse. Buildings are also evaluated based on their ability to reduce water wastage and promote water conservation using efficient irrigation systems and other water-saving measures.
- Water quality: This includes assessing the treatment of wastewater, the management of stormwater runoff, and the protection of water quality in natural waterways surrounding the building.
- Water management: Assesses the overall water management practices of a building, which includes assessing the implementation of water management plans, monitoring and reporting of water usage, and the engagement of building occupants in water conservation practices.
“The idea is to have one New Build rating tool that can be applied to a wide range of building typologies. This update will provide the framework to guide positive change and align to global trends and commitments around sustainability. The tool has an even greater focus on water and will provide a calculator to better predict the estimated water usage of the designed building. It will retain the need to include an effective metering strategy and provide a building tuning process to ensure the designed initiatives are in fact operating as intended. A new requirement has been added which considers the operational resilience of the building’s water supply system. There is a focus on water from a design perspective,” explains Coville.Energy Water Performance Tool (EWP) The EWP toolbenchmarks water performance for offices. Developed by the GBCSA, the EWP assesses the performance of both water and energy use. The calculator uses benchmarks, created from industry using actual performance and assesses water performance relative to a benchmark. It can assist building owners in understanding where their office building performance sits in relation to other similar office buildings in industry, as well as in relation to other buildings in their own portfolio. This is a fantastic tool for making decisions on which buildings to retrofit, hold or sell, and also becomes a powerful communication tool to prospective tenants or buyers. Net Zero Water Tool The Net Zero Waterrating tool helps building owners, designers, and operators achieve a net-zero water use goal. When a building is able to consume as much water as it produces it achieves a Net Zero rating. The rating is structured in a way to reward projects which have achieved Net Zero at the design stage (modelled) as well as operational phase (measured) of a building’s lifecycle. Excellence in Design for Greater Efficiencies (EDGE) Tool The EDGE tool is a building certification system developed by the International Finance Corporation (IFC), a member of the World Bank Group. It is a resource efficiency assessment/certification tool and assesses a building’s water performance in three key areas:
- Water consumption: Assesses the total water consumption of a building. The tool calculates the water consumption based on various water use measures. This covers for example sanitary fittings, landscaping and appliances
- Wastewater: The tool evaluates whether the building has implemented any measures to treat and reuse the wastewater. It also considers if rainwater is harvested and reintroduced into the building.
- Water efficiency: Calculates the efficiency of a building’s water use by comparing its water consumption and harvested water to a baseline value. The baseline value is calculated based on the water consumption of a reference building with similar occupancy and local water use characteristics.