Build Our Green and Carbon Neutral City by Turning Wastes into Valuable Materials

A green and salubrious environment paves a road to a good life for us. It is a goal we should pursue with concerted efforts. In October last year, the HKSAR Government put forward the vision of “Zero-carbon Emissions。Liveable City。Sustainable Development” in the “Hong Kong's Climate Action Plan 2050”, stating that Hong Kong will be committed to achieving carbon neutrality by 2050. Regarding carbon reduction, “Waste Treatment” is one of the three key areas, and “Energy Saving and Green Buildings” is one of the four major strategies. Both tactics are closely related to the construction industry.

Comprehensive waste management can improve construction projects in many ways. First of all, reducing wastes caused by damage during use, treatment and storage could lower transportation and waste disposal expenses. It lessens the total costs incurred. In addition, waste reduction can cut down space taken up in the landfill and moderate negative impacts on the environment. Additionally, minimizing onsite work could improve the tidiness of construction sites, consequently, avoiding issues caused by unhygienic conditions and enhancing industrial safety.

Prepare a Waste Management Plan during Pre-construction Phase for Multiple Benefits

The CIC recommends that all projects should formulate a waste reduction plan during the planning and design phase. Building Information Modelling (BIM) and Common Data Environment (CDE) should be useful for these preparations. A proper waste management plan should include the following facets: types of major wastes to be reduced, targets, plans, waste disposal procedures, monitoring and audit and performance indicators etc. It will be ideal for industry members to take waste management into consideration throughout the whole construction life cycle. As early as in the stage of inviting tenders, we could ask for waste reduction plans and the adoption of green procurement principles. The synergy effect will be more significant if we make good use of incentives to encourage partners to reduce waste as well. Hence, the result will be even more remarkable.

Adopting the “Modular Integrated Construction” (MiC) method during the construction phase means transferring some onsite work procedures to a more controllable factory environment, which is beneficial to waste reduction and cost saving on manpower. Energy-saving and waste-reduction designs, tools and instruments, such as concrete sensors, automatic skips, treated grey water and reclaimed water recycling systems, should also be extensively applied.

Upon completion of construction, construction wastes can be upcycled to building materials with appropriate sorting and handling. In fact, not all “construction wastes” should be trashed or dumped, they still possess use value and economic value. A considerable portion of these wastes could be reused or converted to recycled materials. Purchasing the leftover building materials from other construction projects can reduce wastes and compress expenses on materials. From the perspectives of environmental protection and economy, both buyers and sellers can enjoy the win-win situation.

Buildings with Waste-to-Energy Facilities In Operation in Hong Kong for Years

Our industry is absolutely capable of constructing buildings with built-in waste-to-energy facilities. Waste-to-energy refers to the process of using technology to convert the energy of wastes into heat or electricity. Take the design of the CIC–Zero Carbon Park as an example, it generates renewable energy on-site through photovoltaic panels and biofuel made of waste cooking oil. It exports surplus energy to offset embodied carbon of its construction process and major structural materials.

T · PARK is another iconic building that combines recreational, educational and ecological features in a single complex. Its waste treatment facilities use high-end incineration technology to process sludge with thermal energy. With two plants and four incineration trains in the facility, it can handle a maximum capacity of 2,000 tonnes of sludge per day. After turning the sludge into ashes and residues, the original volume of sludge is downsized by 90%. This huge cut on the quantity of waste relieves the pressure on the landfills and reduces the emission of greenhouse gases by up to around 240,000 tonnes a year.

These waste-to-energy designs and technologies have gone beyond the concept of “zero-carbon buildings”, our industry can take inspiration and learn from these examples. These two leisure parks located in beautiful and pleasant environments are uniquely crafted. They are open to the public and serve as a fun place for friends and families to visit together. At the same time, we can all learn about the advantages of waste-to-energy facilities and promote the message of “Waste Reduction by All Citizens”.

For new buildings, applying new technologies is one way to cut down wastes disposal. For existing buildings, proper maintenance and repairing is the way to go. At last month's CIC “See What I See” event, Ir Wai Chi-shing, Managing Director of the Urban Renewal Authority (URA), shared his insights on urban renewal. Ir Wai mentioned that the URA has actively encouraged prolonging the lifespan of buildings, so as to slow down the pace of urban decay. This strategy comes with many advantages: raising the living standard of residents in old buildings, directly cutting down on construction and related wastes, and contributing immensely to the sustainable development of our society.

Carbon Assessment Improves Sustainability Performance

The CIC Carbon Assessment Tool (CAT) is a tool to facilitate the industry in setting carbon reduction targets. Its purpose is to assess the embodied carbon of construction materials and carbon emissions of on-site construction process from buildings and infrastructures in Hong Kong. CAT is free of charge. As of now, the Tool is put in place in over 300 public and private projects.

CAT is co-developed by a team consisting of over 200 experts from different sectors. It is empowered by the collective wisdom of experts from the government, academia, builders, contractors, designers and suppliers. Its open data and estimation guide serve as standards and reference for the industry. Carbon emission factors for over 800 construction materials are developed by CAT. Users can use CAT to estimate, analyse and measure embodied carbon of construction materials and carbon emission of on-site construction processes. The results could be certified by a third party and accredited by BEAM Plus. Normally, they are well recognized by carbon audits and Environmental, Social, and Governance (ESG) assessments.

The suggested method for applying CAT is as follows: after conducting site inspections, users can use the CIC Carbon Assessment Tool to make accurate estimates, improving the precision of estimating embodied carbon and carbon emissions from materials and other aspects. CAT offers the following benefits: 1. facilitation of project planning, facility management and cost estimation; 2. reduction in wastes and carbon emissions; 3. improvement in sustainability performance; 4. enhanced efficiency.

In recent years, The CIC has launched a series of large-scale projects and activities on sustainable development, such as “CIC Carbon Assessment Tool”, “CIC Green Product Certification”, “CIC Sustainable Finance Certification Scheme”, “CIC Sustainable Construction Award” etc., advocating the industry to speed up their progress in sustainable development, mutual recognition of standards, and embracing the future of a green economy.

The CIC encourages the industry to commit carbon emissions by voluntary collaborative actions. Last year, the Business Environment Council (BEC) and Gammon Construction jointly drafted the “Power Up Pledge”, proposing that builders should connect temporary power supplies at private project sites as soon as possible, to fulfil the goals of optimization of electricity use and zero carbon emissions onsite. Signatories of the Pledge include the CIC, developers and contractors. The consensus clearly showed the united force of the industry for carbon emissions reduction.

Our industry plays a pivotal role in the following initiatives: waste to energy, waste to resources, nurturing a circular economy, creating employment opportunities and new types of work, fulfilling targets of zero landfill, zero energy waste and zero water waste. The construction industry can contribute to Hong Kong's vision of becoming a green and carbon neutral city in many ways, for example, accelerating the pace of carbon emission reduction and waste reduction, promoting sustainable buildings, and implementing low-carbon construction measures. Our future success will be assured by our actions and love for the city.