Green building design focuses on maximising the resource efficiency of buildings and minimising their adverse effect on the environment. In recent years, water conservation has become a critical factor in green building design and construction. According to the United Nations Environmental Program, buildings consume 20 percent of the world’s available water, a resource that becomes scarcer each year. With intensified droughts and a growing population, the demand for water has never been greater. The challenges for water conservation are many, but green buildings offer numerous water saving techniques.
Rainwater Harvesting & Greywater
The first step for increasing water efficiency is to reduce the use of drinkable water for non-consumption purposes. There are two ways to do this: collect rainwater, and reuse indoor wash water. You can install cisterns above or below ground that will collect and store run-off rainwater from rooftops and other impervious surfaces. You can use up to 99% of the water collected by this method.
If rainwater is not abundant, you can create a system for reusing water from laundry machines, dishwashers, bathtubs, and sinks. This type of water is classified as greywater. Greywater refers to gently used wastewater that is reused for anything other than drinking, cooking, or cleaning. Many green buildings collect and treat greywater on-site to save on the costs of freshwater as well as the costs of wastewater disposal.
Greywater is especially important for water-scarce areas since it provides a dependable, drought-proof source of water. The most common uses of rainwater and greywater include irrigating outdoor landscaping or flushing toilets.
Faucet Aerators & Low-Flow Fixtures
The primary way of reducing indoor water use heavily depends on the fixtures you choose. Faucet aerators are devices that release 30% water and 70% air once they are attached to taps. A faucet or tap aerator is a round plate with holes that spreads a stream of water into small droplets, reducing splashing and thus saving water. Water flowing out of an aerator comes diffused instead of in a solid stream. The use of an aerator reduces the flow of water to about 5 litres a minute instead of 15 litres.
Green buildings utilise low-flush toilets, low-flow showerheads and other water-conserving fixtures to minimize wastewater. Installing low-flow sink and bathtub faucets, showerheads and toilets can reduce indoor water use by 30-40%.
Smart Irrigation For Watering Lawns
Lawns require a significant amount of water to maintain. On average, 30% of the water used for watering lawns will be wasted. Green buildings save water by implementing smart outdoor irrigation technology. Irrigation controllers can track factors like temperature or precipitation to avoid over-watering your plants and landscaping. You can save even more water by replacing spray sprinklers with drip irrigation, which can be placed under your lawn. This delivers water directly to where the plants will absorb it, thus improving its efficiency.
Indigenous & Drought-Resistant Plants
Using drought-resistant plants or plants indigenous to your area greatly reduces your water consumption. Since indigenous plants are already adapted to your climate, they require less water to thrive. Indigenous plants also have lower maintenance costs; while a lawn must be mowed often, an indigenous plant garden is self-sufficient once fully established.
Green buildings utilize drought-tolerant landscaping, which minimises irrigation costs. The landscaping is characterised by smart irrigation systems that adjust to the weather and alerts so that leaks can be addressed quickly.