Documenting Change: Lesson Three – University of Kentucky College of Design
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Documenting Change: Lesson Three

Impacts from the Built Environment

construction site

by Emily Bergeron

The Intergovernmental Panel on Climate Change (I.P.C.C.) has attributed climate change to the increase in anthropogenic greenhouse gas concentrations. Methane and nitrous oxide concentrations have increased dramatically since preindustrial values, and carbon dioxide emissions have risen more than 70% since 1970. The building industry is the most significant contributor to this rise in carbon dioxide, both directly and indirectly.

Buildings provide us with shelter as well as places to work, sleep, eat, and play. We are affected by their form, color, materials, space, and style. They capture society’s cultural, social, and historical narratives, helping us remember, understand, and connect to our past. They also connect us to our community and to place. They are one of the most significant and costly products of human activity. Buildings have an enormous impact on our lives and, more broadly, on the environment and economy. Construction activities impact the environment throughout the life cycle of development. These impacts occur from initial resource extraction for materials through work on-site through the construction period, operational period, and to the final demolition when the life of a building ends. The industry contributes to climate change, air pollution, water pollution, habitat destruction, and landfill waste.

The life cycle of a building can be divided into the extraction of necessary raw materials, processing or manufacturing of construction materials and building components, transportation and installation of these materials, operation, maintenance, and repair of the building, and demolition and disposal at the end of the lifecycle. Each phase places demands on and impacts the environment. So what exactly are the effects of construction?

Emissions

Building materials like concrete, brick, steel, aluminum, wood, glass, copper, asphalt shingles, and all sorts of plastics, from vinyl flooring to weatherproofing house wrap, all create greenhouse gas emissions. Steel and concrete, in particular, require heating raw materials to high temperatures, with the energy typically coming from fossil fuels contributing large amounts of GHGs. Cement for concrete is responsible for 7% of the world’s carbon emissions.[i] Steel creates 2.3 tons of carbon for every ton of metal produced.[ii]Aluminum is another high emitter, causing 3% of the world’s direct industrial CO2 emissions.[iii] Overall, 37 percent of energy and process-related CO2 emissions come from construction.[iv]  In 2021, CO2 emissions from buildings reached ten gigatons, the highest level to date.

Energy Consumption

The environmental impact of construction that accrues during the entire life cycle of a building includes energy consumption. According to the United Nations, the construction industry was responsible for 34 percent of energy demand and around 37 percent of energy and process-related CO2 emissions in 2021.[v]The U.S Green Building Council (U.S.G.B.C.) estimates are higher, placing the construction industry accounting for 40% of worldwide energy usage. Construction also accounted for 37 percent of “energy and process-related” emissions.[vi] At this rate, emissions from commercial buildings are expected to grow 1.8% in this decade alone.

In the United States, energy consumption by the residential and commercial sectors represents the majority of energy consumption in all U.S. buildings. Private households use this energy for space heating, water heating, air conditioning, lighting, refrigeration, cooking, and running appliances. The commercial sector broadly includes service-providing facilities and equipment for businesses, various levels of government, and other private and public organizations. The uses are similar to residential. In 2021, the combined residential and commercial end-use energy consumption approached 21 quadrillion British thermal units (Btus), or 28% of total U.S. end-use energy consumption.[vii]

Energy consumption during the construction of buildings needs to be better understood. The process from start to finish is fragmented and involves many parties.[viii] This makes it difficult to predict the energy required or its impact during construction. Although researchers often exclude the construction phase in determining lifecycle energy consumption, European and U.S. figures have estimated this portion to be about 7-10% of total embodied energy.[ix]

For more information on energy consumption, see:

Pollutants and Waste

Materials used in and released during construction, from past and present, are known to cause harm to the surrounding environment – air, water, and land. Land clearing, diesel engine operation, demolition, burning, and working with toxic materials contribute to air and water pollution. Construction and demolition create windblown problems— fugitive dust— which can linger for days or even weeks. Dust and other emissions include toxic substances such as nitrogen and sulfur oxides. They are released during the production and transportation of materials and from site activities and have caused a severe threat to the natural environment (Spence & Mulligan, 1995; Ofori & Chan, 1998; Rohracher, 2001). Other harmful materials, such as chlorofluorocarbons (C.F.C.s), are used in insulation, air conditioning, refrigeration plants, and fire-fighting systems and have seriously depleted the ozone layer (Clough, 1994; Langford et al., 1999). Construction materials such as lead, volatile organic compounds, chromated copper arsenate, asbestos, silica, and polyvinyl Chloride (P.V.C.) are all pollutants associated with harmful health and environmental impacts. Noxious vapors also impact air quality from oils, glues, thinners, paints, treated woods, plastics, cleaners, and other hazardous chemicals. On-site negligence has also resulted in toxic spillages, which are washed into underground aquatic systems and reservoirs (Kein et al., 1999). In addition to toxins, construction sites also create much noise as workers use heavy machines and equipment and light pollution where new or temporary lighting may be installed, and large areas are floodlit.

The process also creates vast amounts of C&D waste comprised of building materials, construction debris, remodeling, repair, and demolition of structures. Specifically, steel, wood products, drywall and plaster, brick and clay tile, asphalt shingles, concrete, and asphalt concrete are used in the E.P.A.’s estimate of C&D debris generation. The agency determined that in 2018, the United States recorded 600 million tons of construction and demolition waste, making it the country’s most prominent individual solid waste stream.[x]Construction creates an estimated one-third of the world’s overall waste. Demolition represents more than 90 percent of total C&D debris generation, while construction represents less than 10 percent. Just over 455 million tons of C&D debris were directed to reuse, and just under 145 million tons were sent to landfills. Aggregate was the primary subsequent use for the materials in the C&D debris.[xi]

For more on pollution and waste, see:

Resource Scarcity

The construction industry uses more materials by weight than any other industry in the United States. More than 100 billion tons of raw material, the equivalent of two-thirds of the mass of Mount Everest, are removed from the planet every year.[xii] Half of that is sand, clay, gravel, and cement used for building. The E.P.A. has found that construction activity accounts for half of all the resources extracted from nature, one-sixth of global freshwater consumption, one-quarter of wood consumption, and one-quarter of global waste. Forty percent of these resources alone are turned into housing. Before the pandemic, consumption increased by more than 8 percent; however, the reuse of resources dropped from 9.1 to 8.6 percent.

For more on resource consumption and construction, see:

Biodiversity

The built environment is a significant driver of biodiversity loss. Biodiversity is the variety of life on earth — its ecosystems, habitats, and species. Development inevitably impacts biodiversity, destroying and diminishing habitats, ecosystems, and food sources. Development also impacts landscape connectivity, animal movement, and other ecological flows, inhibiting wildlife movement and their ability to meetbiological needs. This may lead to higher wildlife mortality, lower reproduction rates, smaller populations, and lower viability. More subtle impacts further down the line also result from these activities. For example, noise and light pollution during the construction process may disrupt species’ breeding and feeding behavior patterns and ultimately lead to population decline later. It may also lead a particular population to relocate to another area, reducing the biodiversity surrounding the development. Previously mentioned extractive practices to supply the materials needed for construction, such as timber, sand, and gravel, can alter or destroy habitats through removal. Additionally, noise, air, and water pollution can be secondary impacts. Converting raw materials for construction use creates even more pollution and waste and, by utilizing fossil-fuel-based energy sources, contributes to climate change, the single greatest threat to biodiversity.

For more on biodiversity, see:


[i] PBL Planbureau voor de Leefomgeving. “Trends in Global CO2 Emissions: 2016 Report.” PBL Planbureau Voor De Leefomgeving, 30 Aug. 2017.

[ii]  “Mission Possible Sectoral Focus: Steel: ETC.” Energy Transitions Commission, 4 Jan. 2023.

[iii] Iea. “Aluminium – Analysis.” IEA.

[iv] Environment, UN. “2022 Global Status Report for Buildings and Construction.” UNEP.

[v]CO2 Emissions from Buildings and Construction Hit New High, Leaving Sector off Track to Decarbonize by 2050: Un.” UN Environment.

[vi]CO2 Emissions from Buildings and Construction Hit New High, Leaving Sector off Track to Decarbonize by 2050: Un.” UN Environment.

[vii] Monthly Energy Review, Tables 2.2 and 2.3, December 2022.

[viii] Sharrard, A.L., H.S. Matthews, and M. R.O.T.H., “Environmental Implications of Construction Site Energy Use and Electricity Generation,” Journal of Construction Engineering and Management, Vol. 133, No. 11, 2007, pp. 846–854.

[ix] Kohler. Life Cycle Cost of Building. in Buildings and the Environment. 1991. University of British Columbia; Cole, R.J. and D. Rousseau, “Environmental auditing for building construction: Energy and air pollution indices for building materials,” Building and Environment, Vol. 27, No. 1, 1992, pp. 23–30.

[x] EPA. “Facts and Figures About Materials Waste and Recycling.” EPA, Environmental Protection Agency.

[xi]Construction and Demolition Waste.” Environment.

[xii]  PACE. “Circularity Gap Report 2021.” CGR 2021, 2021.