Water Neutrality: A new perspective for sustainable construction in the UK
The scarcity of water is a rising issue for the stability of the ecosystem and it can be an impediment to meeting the water demands of buildings in the construction sector. The availability of water has the potential to be a decisive factor in the growth of the construction industry in the United Kingdom. The excessive use of water has become a severe problem and it can restrict new developments in construction. This is because excessive water consumption influences the quantity and quality of available water for new structures in the construction industry. The consumption of water for different purposes by a community is called water footprint.
The UK has never faced a severe crisis related to water scarcity and water proficiency. However, it doesn’t mean the UK construction industry has to be negligent about improving water proficiency for future developments. Construction developments in the UK can have the potential to pollute water sources. Thus, it would be an issue in the path of achieving a sustainable construction standard. Thus, water neutrality is one of the best options for sustainable construction in the UK.
What is Water Neutrality?
Water Neutrality is a new concept for most of the developments that aim to enhance water management and improve the proficiency of water supply systems. According to the concept of Water Neutrality, the water footprint for a community must be the same after a new development has occurred or a new structure has been built. The new project must be water neutral and doesn’t have consumptive effects on existing water resources.
In other words, the water-neutral construction or any development will not increase the already existing water demands of an area and will have net zero impact on the main water supply of the area in which the project is taking place.
Water neutrality tends to lessen depletion stress over water resources by reducing water consumption, reusing the water, recycling the wastewater on construction sites, and offsetting. Offsetting is usually done by collaboration with water companies that can retrofit water fixtures in buildings and can eradicate or at least minimise the unsustainable use of water.
Water neutrality identifies alternative sources of water for construction projects and minimises water waste to increase efficiency. Figure 1 demonstrates the concept of water neutrality.
The UK industry is focusing on green construction and sustainable developments and water neutrality can largely enhance performance in terms of environmental stability as well as carbon emission from buildings.
Water Neutrality for new developments in the UK construction
Water Neutrality is linked with sustainable and green construction, it will minimise the stress on water resources, the environment, and the infrastructure of the United Kingdom. The concept of water neutrality is not only effective for new construction developments rather it can also be applied to existing residential, commercial, or industrial structures. The scale of water neutrality can vary from small residential buildings to large industrial structures. Water neutrality is evaluated for a certain period of time like 10 years or 20 years (Ashton, 2009).
The concept of water neutrality can significantly benefit the UK construction industry financially, socially, and environmentally. There are different techniques that can be adopted for using wastewater and recycling for construction purposes. The systematic designing and planning of buildings based on water neutrality can harvest water without subtracting it from natural sources.
A study by Water UK shows that about 142 litres are used per capita each day. This means that a family can use about 500 litres of water per day. The residential homes designed on principles of water neutrality can save more than 100,000 litres per year for each residential home. The UK construction industry can save 691 million litres per day of water by 2030 if all residential projects are designed to be water neutral for 10 years (Waterwise, 2019).
Currently, most of the residential, commercial, and industrial buildings in the UK are designed based on old methods that don’t incorporate water neutrality in their designs. These structures are consuming water from the supplies. In turn, these water supply systems are capable of carbon emission.
More than 40kg CO2 is emitted by the water supply of each household in the UK per year. The water-neutral housing system eradicates this problem. According to a survey, new developments in the UK can save carbon emissions from the construction industry by 0.11 MtCO2 per year (Water UK, 2019).
How does water neutrality affect planning permission for developments?
New developments tend to face constraints while gaining planning permission in areas where the water demand is a severe conundrum. Usually, the Planning Application for new developments requires a volumetric assessment of water needs. However, in the areas with severe problem issues, Natural England may impose some objections on the Planning Application. (Dominic Ellis, 2022).
In this scenario, a detailed assessment is required that fulfill the obligations of not stressing the existing water resources. This Planning Application is usually required to contain a limit on per capita water usage (usually less than 90 litres per day), design for water harvesting system, and low-water usage measures (Andy Johnson, 2021). However, the water neutrality concept helps to fulfill all those requirements and it is easy to get Planning approved even in areas with water demand problems.
Solutions to achieve water neutrality
There are plenty of methods to achieve water neutrality. Some of the methods are discussed below:
Reduce water consumption
Water neutrality can be achieved by saving the consumption of water per day. The daily water consumption within buildings and households can be reduced by using smart and efficient water control devices. Ensure that these devices have a moderate flow rate that reduces consumption. Water controlling devices that are given the highest rating by the European Water level must be installed.
Promoting water-saving culture can also reduce water consumption in households. Consumers can use smart meters for checking their daily consumption and keeping it low.
Re-use water
This system allows the use of wasted water for purpose of washing toilets, laundry, and irrigation. There are different techniques available to recycle the water and reuse it for non-potable purposes.
Rainwater harvesting
This system of rainwater collection allows capturing runoff water from storms and rain and use it for household purposes like toilets, and irrigation. Rainwater harvesting can serve as an alternative source of supply, thus not subtracting water from the main supply. However, this system is usually implemented on a smaller scale.
There are two types of rainwater harvesting systems: pump system and gravity system. The gravity system is simple in nature as it just requires a catchment for the collection of water or a storage tank on a roof that will collect and supply water. The other system is a pump based system and it is complex. This system is adopted when there are more than one household being supplied with harvested water.
Benefits of rainwater harvesting
- Rainwater is usually clean from impurities and dissolved particles and it is an absolutely free source of water.
- It provides consumers control over the water supply system. It benefits consumers in areas where water restrictions are imposed on users.
- It serves as an alternative source of water and takes stress off the mains water supply.
- It also reduces the water cost of water for consumers.
- Rainwater harvesting subsides the drainage problem of a community. The run-off water of rain can cause drainage problems.
- Rainwater harvesting doesn’t involve complex and expensive technology. Thus, it is easy to maintain and cheap.
- Harvested water can be a necessary backup in the wake-up of emergencies like fire.
Greywater treatment
This system aids in capturing used water from basins, toilets, and washrooms. The used water instead of going to the sewer is directed toward a greywater treatment plant where it is refined for reuse. This system is useful for the construction of commercial buildings like hotels. A greywater treatment plant can be designed based on regulations of British Standard BS 8525-1:2010.
Offset water
This is the final strategy to achieve water neutrality in either new developments or existing structures. Offsetting is usually done with the assistance of local water organisations. In this method, water waste from the existing mains supply is reduced by introducing fittings. These fittings help to save water which is usually wasted.
Conclusion
Water Neutrality can benefit the construction industry of the UK in terms of reducing costs, carbon emissions, and waste. However, the concept is yet to be fully realised to meet Sustainable Development Goals. Figure 2 concludes the entire process of water neutrality.
Where can people find out more information?
Andy Johnson. (2021). Water Neutrality for Sustainable. Patrick Parsons.
Ashton, V. G.-W. (2009). Delivering water neutrality: measures and funding strategies. Environment Agency.
Davies, J. (n.d.). Rainwater Harvesting Systems. Retrieved September 28, 2022, from Great Home: https://great-home.co.uk/rainwater-harvesting-systems/
Dominic Ellis. (2022, March 22). Construction firms must focus on water neutrality. Retrieved from Construction Digital: https://constructiondigital.com/epc/construction-firms-must-focus-on-water-neutrality
ecovie. (n.d.). Greywater Recycling – An Untapped Water Resource Inside Buildings. Retrieved 9 28, 2022, from ecovie: https://www.ecoviewater.com/tech-articles/greywater-recycling-inside-buildings/
Lydia Makin. (2021). Water Nuetrality; Practical Guidance. Waterwise.
Water UK. (2019). Retrieved from https://www.water.org.uk/wp-content/uploads/2019/12/Water-UK-Research-on-reducing-water-use.pdf – Based on there being 0.12kgCO2 embedded in the production of water delivered to an average home per day multiplied by 365 days
Waterwise. (2019). Retrieved from https://waterwise.org.uk/.well-known/captcha/?r=%2Fwp-content%2Fuploads%2F2019%2F10%2FWEStrategy001EXT_TechnicalReport_2.4.pdf
