How developers can help save environment: using low water footprint construction
Water footprint Definition: The fresh water required either directly or indirectly throughout the life cycle of the building which includes water used in the construction, operation, as well as the hidden water used in the manufacture of the materials used in construction.
The construction industry is a very important contributor to the global economy that shapes the future of the cities and infrastructure development. Building and construction account for more than 15% of the total freshwater usage. The water footprint of the construction industry and the building materials are contributing to a negative face of sustainability, leaving an indelible mark on the available water resources.
Construction materials play a pivotal role in shaping the industry’s water footprint. The average embodied water consumption in Indian urban buildings is around 27.6 Kl/sqm of the total built-up area. The split-up between the actual construction consumption to the embodied water of the building materials was found to be 2 Kl/sqm and 25.6 Kl/sqm (Bardhan, 2011).
Lifecycle of Water in a Building
The water usage of the overall lifecycle of a building is defined as three different categories-
- Virtual water (During Manufacturing)
- Induced water (During Construction)
- Operational water (Post Construction)
- Virtual water: It refers to the hidden water embedded in the cradle to gate and cradle to site stages of a material. Knowing the virtual water content of the material helps us to take informed decisions about the selection of materials. This stage forms the first part of the embodied water and is termed as virtual water component.
The virtual water footprints of some of the conventional and sustainable construction materials are mentioned in the table below.
- Induced water: The induced water pertains to the water usage at the site and the project’s duration. Induced water during construction stages include the process of curing, mixing, water used for cleaning and sanitation, and other essential needs. The following table gives the amount of induced water required during construction.
3. Operational water: The direct water consumption on the construction site is termed as operational water and it is measured in litres per capita per day (lpcd). The water requirement for sanitation, landscape, heating, cooling, and other water–consuming activities is covered under operational water. The operational water quantity varies for different typologies and locations. The average water use for different building types are mentioned in the table below.
Sustainable water management practices during construction
Efficient water use is the key to sustainability. Techniques to improve water savings at every stage of the construction, from the selection of materials during construction and post-construction. Some of the strategies to conserve water in construction are:
- Replacing materials with high virtual water content. For example, use fly ash as a replacement to cement in concrete.
- During construction, use recycled water for curing, cleaning, etc.
- Using alternative curing methods like drip curing, membrane curing, etc.
- Using dry mortar skips the need for curing and helps in water conservation in the pre-construction phase.
- Proper management of water resources like harvested water and recycled water and help in cleaning like works.
- Incorporating water-saving fixtures, water sensors and water meters can reduce water consumption by 30% – 40%.
Sustainable operational water management strategies
Implementing strategies like rainwater harvesting and grey water recycling further reduces operational water use and minimise environmental impact. These practices ultimately lead to more resource-efficient and environmentally friendly buildings and can contribute significantly to achieving water sustainability goals in the building sector. Efficient water use in buildings can result in cost savings, increased resilience to water scarcity, and enhanced well-being. Overall, managing operational water use among all building typologies and locations is needed for achieving sustainable water consumption.
Conclusion
In the face of climate change and growing water scarcity, it is crucial for the building sector to embrace sustainable practices and conserve water for environmentally conscious buildings. Life cycle assessment of water can help quantify the overall impacts of construction materials, including virtual, induced, and operational water. A holistic approach is needed to address the environmental, social, and economic impacts of construction practices on water footprints.
At McD BERL, we consider water conservation as a pivotal strategy and design sustainable solutions. We have created a net positive water campus that have achieved more than 80% freshwater savings through water-efficient fixtures and 100% recycling and reusing the treated wastewater. Reach out to info@mcdberl.com to know more about how to achieve self-sustainability and water-efficient designs.
