Climate change mitigation has become a priority issue, with the architectural industry accounting for 38% of global energy-related CO2 emissions. In December 2015, the Paris Agreement proposed to limit global warming to less than 2 ℃ above pre-industrial levels and strive for no more than 1.5 ℃. The architectural industry must achieve net zero carbon emissions by 2050 in order to meet the Paris Agreement's goal.
China proposed at the 75th Session of the United Nations General Assembly on September 22, 2020, that "China will work to peak carbon dioxide emissions before 2030 and achieve carbon neutrality by 2060." It has defined its carbon neutrality goal and execution approach in order to solve global climate and environmental concerns effectively.
Life Cycle Assessment (LCA) is a method for creating an picture of the overall environmental impact of a product's lifecycle from raw material extraction, through production processes and waste management, including all transport and all intermediate energy use. In the situation of architecture, LCA is used to assess the carbon emissions generated by the materials, construction, and use of the structure over its entire life, including demolition and disposal.
In addition to the more conventional architectural and technological approaches, such as optimizing natural light and boosting the envelope's insulation, etc. We may explore the road toward net carbon buildings by exploring methods to reduce emissions throughout every stage of the building's life cycle.
01 Product stage
Different building materials have varying CO2 emission qualities. The Centre for Industrialized Architecture (CINARK) at the Royal Danish Academy developed a digital version of the Construction Material Pyramid utilizing the food pyramid's graphical language, based on Environmental Product Declarations (EPD). The Environmental Impact of Construction Materials Pyramid illustrates the environmental impact of a variety of related construction materials. For instance, wood at the bottom of the pyramid has negative CO2 emissions, indicating that it can continue to absorb CO2 even after being harvested from the forest. Additionally, optimization of design affects the amount of material used, which is also crucial.
Additionally, carbon emissions associated with the gathering and transportation of resources must be considered during the product development stage. As a result, collecting materials from surrounding and drawing on local resources are useful methods. The first stage requires rational material collection and use.
Changqi Stadium Bamboo Corridor / Atelier cnS
Bamboo, being one of the few building materials with distinct Chinese qualities, has a rapid growth cycle and is relatively simple to process. Bamboo is an excellent low carbon material in some regions where it is abundant.
This project is located in Changqi Ancient Village, Lubao, Foshan, Guangdong Province. Changqi Village is one of the first batch of ancient villages identified in Guangdong Province. Lubao Town is famous for its tradition of bamboo weaving. The bamboo village on the back of the ancient village is full of Moso bamboo. The project was to renovate an old basketball court located between the village's wind pond and the village's ancient buildings. Atelier cnS chose to use indigenous materials to construct a bamboo corridor for the basketball court. Bamboo corridors are constructed in modular modules that adapt to the village's growth and demands and are easier to remove and recycle in the future.
02 Constructure process stage
Recently, have demonstrated significant construction efficiency, energy savings, and pollution reduction benefits when compared to conventionally constructed buildings. Prefabricated assembly buildings can greatly minimize construction raw material and energy consumption, and can save up to 24.99 % on carbon emissions associated with building construction waste when compared to typical cast-in-place buildings.
Lakeside Plugin Tower / People's Architecture Office
The Lakeside Plugin Tower is a 480-square-meter mixed-use development. It is being developed as a prototype for the Xiong'an New Area in collaboration with the Shenzhen Institute of Building Research, a world leader in sustainable building design and urban planning. To reduce the building's influence on its surroundings, the Lakeside Plugin Tower is built on a distributed concrete pier base.
The entire structure is prefabricated to save money and facilitate construction. The building envelope is constructed separately from the steel structure using a panelized technology developed in-house by our office. The modular Plugin Panels provide maximum flexibility over the course of the building's life. Because the locks are built into the panels, they may be fitted manually using unskilled personnel and a single tool. Throughout the building's life, full parts of each floor can be added or removed as needed without affecting the rest of the structure. This adaptability increases the building's usability while lowering the expense of future renovations.
03 Use stage
Carbon dioxide emissions throughout the use and maintenance phases are primarily caused by heating, cooling, and power generation. Heating and cooling energy usage account for around 22% of a building's total energy consumption. At this stage, the only approach to reduce emissions is to focus on the energy sector. The first is to increase energy efficiency, which can be accomplished through the use of energy-efficient lighting in buildings; the second is to create renewable energy sources that can be used in place of fossil fuels to reduce emissions, such as solar, wind, and geothermal energy.
Nanjing Green Light House / Archiland International
Nanjing's new landmark, zero-carbon building "Nanjing Green Light house" was inaugurated in July 2015. The building is a collaboration between China and Denmark, demonstrating how to balance ecological and modern architectural design methods. It will eventually serve as a high-tech planning exhibition hall for the park.
The first principle guiding the design of the Nanjing Green Lighthouse is to reduce the consumption of energy. Reduce energy consumption to 60% of the Chinese standard demand baseline through "intelligent design." The building has been precisely calculated to achieve maximum energy efficiency through the top and perimeter lighting; cooling and heating are provided by a novel ground-source heat pump system; and ventilation is provided by a "variable air volume" fresh air system. The second is to maximize the use of renewable energy, reducing energy demand by approximately 20% through active design and adoption of renewable energy. The project collects and utilizes all available natural resources, including rainwater and wind energy; solar photovoltaic arrays are installed on top of and around the building.
04 End of life stage
Along with extending the useful life of the building, improved resource optimization and reuse of waste can help accomplish carbon reduction at the end of life stage. According to the inverted waste disposal pyramid, the optimum option is to reuse waste components after demolition. For instance, scrap windows and doors, as well as steel constructions, are recycled and reused. Then there is recycling, which is the act of collecting and processing garbage in order to recycle it.
Zero Pavilion: A Zero Carbon Garden Made in Alibaba / Tenio
The first step toward a zero-carbon garden is to utilize the plant's carbon sequestration for carbon fixation and oxygen release. The second method is to offset carbon emissions generated during the construction process with renewable energy. Additionally, scrap or recycled materials are employed to minimize material consumption in order to produce a carbon-neutral landscape garden.
The zero pavilion's steel framework is composed entirely of recycled steel, while the tree pond in the water is created entirely of discarded computer cases.
In the design phase, all stages of the building's life cycle should be considered comprehensively. From material selection to waste resource management at the end of the building's life, all factors are taken into consideration early in the design process to create a building that is eventually Net Zero Architecture.
Xuhui Demonstrative Project / SUP Atelier
The project demonstrates sustainable architecture with holistic thinking.
The primary structure and envelope are constructed entirely of sustainable materials such as wood and wheat strawboard. The facade is composed of two layers of prefabricated carbonized wood skins that create a cavity between the wood skin and the inner wall, providing shading in the summer and wind protection in the winter. The carbonized wood has corrosion resistance and maintainability, which can also reduce the subsequent operation and maintenance costs.
The main part of the project is divided into three relatively independent units. Architectural elements of the 3 units were classified into various groups of standardized modules with green technology. Through modification and combination, these modules can adapt to various spaces and facilitate comparative studies and promotion of sustainable technologies.
The building is designed to incorporate a variety of renewable energy sources, including the combined design of film glass, photovoltaic power generation and top wind board, building roofs, glass curtain walls and external facades; Solar thermal system combined with air source heat pump for heating.
As an experimental platform for prefabricated buildings with zero energy consumption, the project has established an integrated mechanism of the “design-construction-test-feedback” process. Real-time feedback to the air conditioning, fresh air, and other equipment systems for automatic management is achieved by environmental monitoring of the building. Guaranteed to create a suitable climate while conserving electricity. Additionally, the data will be stored and analyzed in order to produce a zero-carbon building prototype.
This article is part of the ArchDaily Topics: The Road to Net Zero Architecture presented by Randers Tegl.
Randers Tegl aims to take responsibility and think sustainable as a part of reaching the goal of Net Zero. Both in terms of how building materials impact the climate and how the materials age, but also with a focus on architecture. That is why Randers Tegl created their sustainable series GREENER, which comes with full documentation in the form of EPD, so it is possible to use the product in technical calculation programs.
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