Sustainable construction and demolition site management

Sustainable construction and demolition site management is crucial for minimizing the environmental impact of these activities. Construction sites can significantly affect biodiversity, air quality, and resource management. The construction sector contributes to 23% of air pollution, 40% of drinking water pollution, and 50% of landfill waste. By implementing sustainable practices, it is possible to reduce these impacts, contribute to environmental preservation, and improve working conditions for construction personnel. This blog post will focus on four key aspects: waste management, water management, emissions and energy management, and worker health, safety, and well-being.

Waste Management

Waste management on construction sites is a crucial issue for the sustainability and efficiency of projects. It is estimated that more than 75% of waste generated by the construction industry has a residual value and is not currently reused or recycled. Construction and demolition (C&D) waste resulting from the construction sector accounts for 30% of total waste produced globally, with an estimated average of more than 35% of all C&D waste disposed of in landfills annually.

In Thailand, particularly in the Bangkok area, C&D waste is a significant concern due to the prevalent practice of demolishing or renovating existing buildings. This leads to the generation of construction waste at an average rate of 5.81 tons per 100 square meters of building construction permit, equivalent to an average of 3,173 tons of waste per day. Approximately 70% of this waste is composed of concrete, followed by brick, steel, ceramic, and tile.

Solutions for Waste Management:

• Sorting and Separation at Source: Facilitate the sorting of waste directly on-site to maximize recycling. This involves separating inert waste from hazardous and non-hazardous waste, improving recycling rates.

• Reuse and Recycling: Encourage the reuse of materials and the recycling of construction waste. For example, rubble can be crushed and reused as aggregate for new constructions.

• Construction Waste Management Plans (CWMP): Implement a CWMP to plan and organize waste management throughout the project, including strategies for reduction, reuse, and recycling.

• Training and Awareness: Train workers in waste management and the importance of sorting. Raising team awareness is essential for effective waste management.

Life Cycle Analysis (LCA)

LCA is an essential tool for assessing the environmental impact of materials and processes used in construction. LCA measures environmental impacts at every stage of a product's life, from raw material extraction to building construction and operation, and finally to the end of the building's life or demolition. It is crucial in waste management as it helps understand the complete lifecycle of the materials used, optimizing their use, and minimizing waste generation. To learn more about LCA for buildings, visit our dedicated blog post.

Water Management

Water consumption on construction sites is an environmental concern. For large construction projects such as office buildings, shopping centers, or significant infrastructure, water consumption can reach tens or even hundreds of thousands of liters per day.

Water is used at various stages of the construction process. For example, cleaning painting equipment can consume large quantities of water. Cleaning a single paint roller at the tap can use between 30 and 50 liters of water per day, which, multiplied by the number of workers on a site, represents a considerable volume of water consumed daily. To reduce this consumption, specialized washing stations can be used, limiting the volume of water needed. Similarly, soil treatment can consume up to 80 cubic meters of water per day. The use of efficient water distribution systems and their regular maintenance can help reduce this consumption.

Installing temporary water meters on construction sites is crucial for monitoring water consumption and quickly detecting leaks. It is estimated that globally, water loss due to leaks in water distribution networks amounts to approximately 126 billion cubic meters per year. Additionally, it is during the construction phase that there is the highest likelihood of creating a leak due to construction equipment, mishandling, installation errors, or other factors. Implementing monitoring systems and documenting water consumption is crucial for effectively managing this resource and preventing unnecessary losses.

To mitigate the environmental impact, several practices can be implemented. Using rainwater harvesting systems for non-potable needs is an effective approach. Raising construction teams' awareness of good environmental practices and establishing water consumption monitoring systems also help manage this resource better. Additionally, adopting techniques such as the Water Footprint Network method ("Water Scarcity Indicator"), the Pfister method ("Water Stress Index"), and the AWARE method ("Relative Available Water Remaining") can help assess and minimize the water footprint of construction projects..

Emissions and Energy Management

The construction sector is a significant contributor to energy consumption and greenhouse gas (GHG) emissions. Globally, the construction industry is known to account for approximately 36% of global final energy use and 39% of energy-related carbon dioxide (CO2) emissions. Concrete, one of the most used materials in construction, is responsible for around 8% of global CO2 emissions. This is particularly relevant for Thailand, where urbanization and infrastructure development are driving high demand for concrete.

To reduce emissions and energy consumption on construction sites, several solutions can be implemented:

• Use of Low-Emission Equipment: Adopting electric or hybrid construction machinery can significantly reduce the use of fossil fuels. Using high-performance systems, such as an ENERGY STAR® certified water pump, can save up to 30% energy compared to conventional pumps on a construction site.

• Use of Eco-Friendly Materials: Utilizing eco-friendly materials and innovative forms of concrete can help reduce emissions. For example, recycled concrete can lower CO2 emissions by about 10% compared to standard cement, with only a 2-3% higher investment cost compared to traditional concrete. Recycled concrete also helps reduce construction waste sent to landfills, contributing to a more effective circular economy. Life Cycle Assessment (LCA) is an essential tool for evaluating the environmental impact of materials throughout their life cycle, prioritizing low-emission certified materials.

• Renewable Energy: Installing renewable energy sources, such as solar panels, can power construction sites and the buildings under construction.

• Monitoring and Optimization: Implementing real-time energy consumption monitoring systems can help identify and correct inefficiencies

Worker Health, Safety, and Well-being

Air pollution on construction sites poses a major health risk to workers. Sources of pollution include combustion smoke, exhaust gasses, refrigerants, volatile organic compounds (VOCs), dust, and organic waste. These pollutants can cause respiratory problems, cardiovascular diseases, and exacerbate pre-existing conditions such as asthma. To mitigate these risks, several solutions can be implemented:

• Construction Techniques: Use prefabrication and mechanical fastenings to reduce the use of adhesives. Prefabrication allows elements to be prepared in factories, limiting pollution-generating operations on-site. Mechanical fastenings, such as bolts and screws, replace chemical adhesives, reducing VOC emissions on site.

• Materials: Choose untreated finishes, low-VOC materials, and apply less polluting techniques. Use environmentally labeled materials and apply products with rollers instead of sprays to reduce the dispersion of harmful particles for instance.

• Equipment Use: Regular maintenance of equipment to reduce emissions and use of protective equipment. Proper maintenance of machines prevents refrigerant leaks and reduces exhaust emissions. Provide workers with appropriate personal protective equipment (PPE), such as respiratory masks, to limit their exposure to pollutants.

• Organization: Establish specific zones, protocols, and procedure guides, and train workers. Delineate specific work zones for dust and pollutant-generating activities, establish strict protocols for handling hazardous substances, and train workers in best practices to minimize exposure risks.

Noise on construction sites is a source of nuisance and a health risk for workers. Depending on its intensity, noise can cause discomfort, temporary hearing sensitivity loss, and even deafness. Here are some examples of noise levels on a construction or demolition site and their impact on workers' health:

Noise Levels	Equipment	Impact
80 to 95 dB	Truck, non-soundproofed compressor, paint gun	Pain
95 to 110 dB	Percussion drill, circular saw	Danger
> 110 dB	Pneumatic hammer, drill in an enclosed space, fastening gun	Irreversible lesions

These nuisances affect not only site personnel but also nearby residents. To reduce noise nuisances, several measures can be implemented:

• Organization: Group noisy work into specific time slots, plan to avoid noisy activities during sensitive hours, regularly check noise levels, and communicate with neighbors to inform them of periods of intense noise.

• Design: Choose designs and materials that reduce noise, such as using self-placing concrete to avoid the use of vibrators.

• Technical Devices: Use soundproofed machines and equipment, wear PPE such as earplugs or noise-canceling headphones, and implement collective protection devices (CPDs) such as noise barriers and anti-vibration mats.

Safety on construction sites is a critical concern in Thailand, particularly due to high risks from handling heavy materials, working at heights, and using machinery. Bangkok recorded the highest number of accidents in 2021, with building construction having the highest risk at 5.77%, resulting in 4,516 injuries or fatalities. To improve safety, employers must implement strict protocols, provide regular safety training, and ensure all workers use appropriate personal protective equipment (PPE). Regular audits and engaging workers in safety discussions can also help create a safer work environment.

Conclusion

Sustainable management of construction and demolition sites is crucial for minimizing environmental impact and improving working conditions. By implementing solutions such as waste sorting, using eco-friendly materials, installing renewable energy sources, and setting up real-time monitoring systems, it is possible to reduce greenhouse gas emissions and energy consumption. Life Cycle Assessment (LCA) plays an essential role in providing a comprehensive evaluation of the environmental impact of materials and processes used. By adopting these practices, the construction sector can significantly contribute to environmental protection and promote sustainability.

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