The stern and unpredictable implications of climate change, such as elevated temperatures and melting snow, are pushing humans into high alert. Any effort, no matter how tiny, might alleviate the strain on the environment. Water conservation is essential for resolving water scarcity, safeguarding ecosystems, reducing climate change, enabling sustainable development, and increasing energy efficiency. It is a collective responsibility to protect and prudently manage this priceless resource for both the present and the future. One of the main areas to consider for builders, architects, and other related professionals is water conservation, along with power and energy, in response to the drive for more ecologically sensitive structures. Architecture can assist in fostering a more intelligent connection with the resource, both in terms of lowering our water consumption and reestablishing natural systems. Water efficiency that employs technology and tactics to mitigate the consumption of potable water used in buildings accounts for a substantial portion of green buildings. A responsibly designed building should encourage smarter use of water during the construction phase, indoors and outdoors as well.
Water conservation techniques through architecture
Water conservation measures
To collect and store rainwater for non-potable needs like irrigation, cooling systems, and toilet flushing, architects can include rainwater harvesting systems in buildings. The slab or roof of the building serves as the catchment area in most cases, although other surfaces, like a road or a square, can also be used to collect water. To effectively collect rainwater, architects might add sloped or flat roofs with the proper gutters and downspouts. The design should limit debris accumulation and contamination, and the roof surface material should be ideal for collecting water. Through design elements like an improved bowl, aerator, and flush valve design, low-flow plumbing fixtures, such as flush valves for toilets, urinals, faucet aerators, and showerheads, have been further developed to save significant amounts of water compared to conventional fixtures while providing the same utility. Buildings for water conservation can also be designed with effective cooling systems that use the least amount of water. Water usage can be decreased, for instance, by adding evaporative cooling methods or switching to air-cooled systems from water-cooled ones. More effective watering is made possible by integrating smart irrigation systems with moisture sensors and weather information such as drip irrigation or micro-sprinklers. Based on actual needs, these systems modify watering schedules, minimizing water waste. When hot water pipes are improperly insulated, the user must wait before turning on the tap or the shower. Up until the consumer receives the hot water, a lot of water is squandered. As a result, a household hot water delivery system’s pipelines and storage containers need all be insulated.Small leaks result in significant water loss over time. One litre of water is lost due to around 4000 drips, and this sum quickly builds up. This costs the building owner money and hinders water conservation. Because of this, it is best to build with leak protection in mind.
Water reuse/recycling systems
On-site, minor filtering or treatment to recycle water from the same source at the same place can be done. For example, purified water from automobile and laundry washing applications can be used in the subsequent wash cycle. Wastewater from sinks, showers, and laundry can be reused in buildings with greywater recycling systems for things like irrigation, single-pass cooling, and toilet flushing. Non-potable water that can be recycled to comply with wastewater treatment regulations can be utilised for on-site industrial activities as well as end applications like landscape irrigation, decorative fountains, makeup water for cooling towers, toilet flushing, and fire sprinkler systems. Depending on the intended use, treatment systems such as filtration, sedimentation, disinfection, UV sterilisation, or reverse osmosis can be used.
Landscape, xeriscape, and building design
An important area to focus on for water conservation is landscaping water usage, which can easily account for 20% or more of facility water consumption. The natural cooling, water filtration, and air filtration benefits of vegetated landscapes are used as a technology in plant-covered roofs, sometimes referred to as vegetated roofs or eco-roofs, to assist in improving the urban environment. Native or drought-resistant plants can be incorporated into landscaping designs. These plants require less water for irrigation, reducing the overall water demand of the building. Xeriscape emphasises minimising the use of traditional lawns or turf areas, as they typically require significant water inputs. Instead, xeriscape promotes the use of low-water grasses or alternative ground covers that are more suitable for the local climate. Designing permeable surfaces such as permeable pavements or porous landscaping areas allows rainwater to infiltrate the ground, reducing stormwater runoff and the need for irrigation. Architects can optimise building orientation and incorporate shading elements to reduce the cooling demand of the building. By minimising the need for air conditioning, less water is required for cooling towers and other cooling systems.
Case study: The Pixel Building, Australia
Pixel, Australia’s first carbon-neutral office building, is a bearer of perfect 105 Greenstar points and generates all of its power and water on-site. Pixel’s water purification and utilisation system is considered the most advanced ever created. The Pixel Building serves as an example of how water conservation techniques can be incorporated into urban planning projects.
One of the breakthroughs identified is the installation of small-scale vacuum toilet technology. The device, which resembles an enhanced version of an aeroplane toilet, was created for high-quality office and lodging buildings in northern Europe. An efficient conventional toilet would consume 1.28 gallons per flush. However, this device uses only 0.13 gallons. The solution has significantly decreased water usage and ensures Pixel’s continued water self-sufficiency. The ground-level anaerobic digester separates methane from the waste and is made up of a tank system that houses all of the blackwater waste generated by restroom and kitchen facilities. The residual blackwater waste is then transported to the sewer in liquefied form with lower methane levels while the gas captured is used to substitute natural gas for heating and cooling the water system. These in turn, supply the hot water for the showers, which then generate the grey water required to irrigate the reed beds and eliminate the requirement for fossil fuel gas to support the solar hot water system while likewise minimising methane emissions.
Reuse of water is accomplished on various levels. Rainwater that falls on the roof garden of the Pixel building is collected after it is utilised to irrigate the native Victorian grassland plants that have been reintroduced in the roof garden. Reverse osmosis is administered to purify the rainwater, which is first held in tanks. All of the building’s fixtures and fittings receive this treated water, and the resulting grey wastewater is filtered and sent to the living edge reed beds, where it is used to water the reeds and other plants. As a result of this procedure, there is no gray water waste leaving the Pixel site apart from during Melbourne‘s wettest month, therefore decreasing the amount of garbage that is discharged into the sewer.
References:
Wbdg.org. (2016). Water Conservation | WBDG – Whole Building Design Guide. [online] Available at: https://www.wbdg.org/resources/water-conservation.
sftool.gov. (n.d.). Water Efficiency – GSA Sustainable Facilites Tool. [online] Available at: https://sftool.gov/learn/about/45/water-efficiency.
Consulting – Specifying Engineer. (2012). 10 ways to save water in commercial buildings – Consulting – Specifying Engineer. [online] Available at: https://www.csemag.com/articles/10-ways-to-save-water-in-commercial-buildings/.
Carbon Neutral Offices -DRAFT > The Pixel Building Case Study SNAPSHOT Organisation Building type Commercial Offices Project name Pixel Project objective. (n.d.). Available at: https://cdn.archilovers.com/projects/4b28f524-bfac-47eb-93db-cc44f16bd2e4.pdf.
www.studio505.com.au. (n.d.). Homepage – Studio 505. [online] Available at: https://www.studio505.com.au/.
Comment, G. (2021). Water Conservation in Architecture. [online] Thegreensideofpink. Available at: https://www.thegreensideofpink.com/design-en/architecture/2021/water-conservation-in-architecture/?lang=en.
