The carbon impact of the construction sector

Once a structure is constructed, the greenhouse gas emissions (GHG) connected with it, known as "embodied carbon," are by their very nature irreversible. Embodied carbon encompasses all CO2 emissions related to the actual construction activities required for the installation of the materials and all emissions related to the extraction, production, and transportation of materials and equipment to a project site. The lifetime emissions of capital projects are significantly influenced by these emissions produced during construction. The embodied carbon emissions from construction are fixed while the project is carried out, even if operations may have possibilities for decarbonisation years after construction is finished. Close to 50% of total life cycle emissions come from upfront carbon emissions.[i] The building and construction industry's energy consumption and CO2 emissions have returned from the COVID-19 epidemic to an all-time high, despite a surge in investments in energy efficiency and a decrease in energy intensity. The 2022 Global Status Report for Buildings and Construction, unveiled at COP27, indicated that the industry was responsible for over 34% of energy consumption and around 37% of energy- and process-related CO2 emissions in 2021. The sector produced ten gigatonnes of CO2 equivalent in operational energy-related CO2 emissions in 2019, 2% more than the pre-pandemic peak and 5% more than 2020 levels. Buildings' operational energy needs for heating, cooling, lighting, and other equipment grew by about 4% from 2020 and 3% from 2019.[ii]

Adaptive reuse can reduce construction carbon emissions

By renovating existing buildings and repurposing spaces and materials, developers can decrease the amount of carbon associated with new materials and reduce the amount of debris and waste going into landfills. According to the U.S. Environmental Protection Agency, deconstruction rather than demolition can save 90% of a building’s materials. Adaptive reuse strategies are also more cost-effective. Not only is adaptive reuse much cheaper than demolition and new construction, but property owners can also enjoy municipal incentives for converting their properties, some of which may have historic value. Additionally, reuse may have the potential to speed up local approval processes and minimise impacts on neighbours.[iii]

Adaptive reuse can occur at various scales. Below are examples of such strategies at different levels.

• Products
• Reuse, repurpose, recycle: Participate in businesses and procedures that reuse material components, furniture, and office supplies.
• Base reuse of appliances with current demands and energy efficiency: Electronics and appliances might not be as easily recyclable or repairable as other goods.
• Use locally sourced products: Local sourcing can lower emissions associated with transportation, boost neighbourhood economies, and promote recycling.
• Interiors
• Design for disassembly: Use instruments like Whole Building Life Cycle Assessments to develop reduction solutions.
• Select low-carbon materials: Compared to cross-laminated wood, brick, stone, and steel, glass has a higher impact.
• Choose materials that are easy to reuse: The best materials for reuse include carpet, removable walls, and doors, as opposed to drywall, linoleum, and ceiling tile.
• Buildings
• Reposition and retrofit: Consider potential usage in the future and create flexible, multipurpose designs to fully realise potential.
• Assess the core and shell of the building: The slabs, façade, and roof can all be used for different purposes.
• Consider the location: Consideration of enclosure upgrades is heavily influenced by changing local climate conditions.
• Cities
• Examine new uses that meet community need: Adaptive reuse techniques can improve local economies and make cities more sustainable.
• Look for partnership opportunities: Join forces with local governments to develop infrastructure, net zero, and community planning strategies.
• Connect with your community: Reusing structures may be justified for historical, social, and cultural reasons.[iv]

The cultural benefit of adaptive reuse creates some powerful stories

By utilising the available resources, communities may unleash the strength and potential of older structures, reviving their neighbourhoods and transforming places that are important to them. Cities can maintain their architectural and cultural history while reducing disinvestment, igniting social change, and pursuing sustainable growth by adapting buildings that have outlived their original uses.[v] West Chester, Pennsylvania, has earned a reputation for pleasant small-town living thanks to a dedication to maintaining the historic charm of its downtown area. A variety of business and residential buildings constructed between 1830 and 1930 line the pedestrian-friendly downtown, the majority of which are recognised as historic sites on the National Register of Historic Places. Breweries have opened in old Woolworth's buildings, Wells Fargo has a location in an 1830s Greek Revival structure that originally held the county's first bank, and a theatre has been converted into a hotel. The Great American Main Street Award, given to communities that are models of preservation-based business district redevelopment, was given to the town in 2017 by Main Street America (a
programme of the National Trust) in recognition of the town's transformation.[vi]

Downtown West Chester

Source: West Chester Magazine

By engaging with adaptive reuse, businesses in the West Chester area have maintained not only the character of their town but also grown their reputation as a bustling commercial centre.

References

[i] McKinsey- Reducing embodied carbon in new construction

[ii] UNEP- 2022 Global Status Report for Buildings and Construction

[iii] Gensler- The adaptive reuse revolution: Reuse strategies at every scale are cost-effective with reduced carbon impact.

[iv] Ibid

[v] NTHP- New Year, New Building: 5 Adaptive Reuse Projects for Historic Buildings

[vi] Ibid

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