The Construction Material Pyramid:
The Construction Material Pyramid is a digital tool inspired by the food pyramid developed by the Center for Industrialized Architecture (CINARK) at the Royal Danish Academy. Published as a poster in 2019, it allows for comparing environmental impacts, mainly CO2 footprints, among different building materials. Using Environmental Product Declarations (EPD) focuses on the initial construction phases (A1–A3) to visualize the environmental impact associated with material production.
The pyramid offers a convenient way to gauge the sustainability of construction materials quickly, facilitating informed decision-making within the building industry. Architects are central to this process, ensuring that material lifespans align with environmental goals, challenging conventional assumptions found in life cycle assessments (LCA).
Environmental impact categories in the pyramid include Global Warming Potential (GWP), Ozone Depletion Potential (ODP), Photochemical Ozone Creation Potentials (POCP), Acidification Potential (AP), and Eutrophication Potential (EP). These categories, commonly used in building-related LCAs, help assess potential environmental, ecosystem, and health damage.
Global Warming Potential (GWP) measures how much heat a greenhouse gas traps in the atmosphere over a specific period, usually 100 years, compared to carbon dioxide (CO2). It quantifies the impact of different greenhouse gases on global warming. The GWP considers a gas’s ability to absorb heat and its lifetime in the atmosphere. Common greenhouse gases included in GWP calculations are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and various fluorinated gases. GWP is quantified using CO2 equivalents (CO2eq) as its standard unit of measurement.
Ozone Depletion Potential (ODP) is the depletion potential of the ozone layer. Thus, this includes the chemical compounds that affect the depletion of the ozone layer. Degradation of the ozone layer increases UV radiation intensity, which damages plants and animal species. The chemical substance freon (R-11eq) equivalents serve as an indicator unit for ODP.
Photochemical Ozone Creation Potentials (POCP) describe the formation of photochemical smog under this category. In high concentrations, ozone can affect the health of humans and nature, especially breathing. POCP is measured using ethylene equivalents (C2H4eq) as an indicator unit. The environmental impact stems largely from volatile organic compounds (VOCs), which can occur in the production and incineration of plastics and paints.
Acidification Potential (AP) delineates the potential effects of acids emitted into the atmosphere in gaseous form or as substances in soil and water. Acidification can harm ecosystems, particularly plants. In the 1980s, "acid rain" was a common topic of discussion. This impact category is quantified using the indicator unit sulfur dioxide equivalents (SO2 eq).
Eutrophication Potential (EP) denotes an excessive load of nutrients that can potentially harm the environment. Over-fertilization of the soil can affect the vegetation and eventually result in its death; the environmental impact is also called "desertification." Over-fertilization can also have the opposite effect, creating optimal conditions for plant growth so that it ends up with the plants outcompeting other living organisms. It can happen, for example, in oceans and lakes, where it can result in algae growth, damaging biodiversity. EP has phosphate as a reference substance calculated in phosphate equivalents (PO4eq).
You can read about how CINARK has tested the ideas behind the Construction Material Pyramid in the book: "Circular Construction – Architecture, Materials, Tectonics" (CINARK 2019).
The pyramid’s categories are based on the European standard CEN/TC350, providing a comprehensive view of environmental impacts.
The Construction Material Pyramid is a practical tool for architects, designers, consultants, and students, facilitating informed decisions towards eco-friendly construction practices. By embracing its principles, they contribute to a gradual but impactful transition towards sustainability within the construction industry.
References:
Center for Industrialized Architecture (CINARK). (2024). Retrieved from: https://www.materialepyramiden.dk
Center for Industrialized Architecture (CINARK). (2024). Retrieved from: https://issuu.com/cinark/docs/circular_construction_080919_low
Vandkunsten Architects. Build Better! The Material Pyramid is interactive (October 28, 2020). Retrieved from https://vandkunsten.com/en/news/material-pyramid