Everything we do impacts the environment, although the degree of impact varies widely according to its source. Says the United Nations Environment Program, the construction sector generates as much as 30% of all greenhouse gas emissions. Activities like mining, processing, transportation, industrial operations, and the mixture of chemical products result in the emission of gases like CO2, CH4, N2O, O3, halocarbons, and water vapor. When these gases penetrate the atmosphere, they absorb part of the sun’s rays and release them as radiation into the air, bringing warmth to the earth. With a quantity of gas released every day, this layer thickens, which causes solar radiation to enter and stay in the planet. Today, this ‘layer’ has thickened to the point that humanity is suffering serious consequences, like desertification, the melting of ice, an insufficient water supply, and the worsening of storms, hurricanes, and floods, which has altered ecosystems and resulted in less abundant biodiversity.
Anyone involved in building design should be focused on the lessening of carbon emissions from our building projects. The ability to measure, quantify, and assign a rating to this quality is imperative.
The phrase Embodied Energy or Embodied Carbon references the summary impact of all greenhouse gas emissions associated with a material throughout its life cycle. This cycle takes into account extraction, manufacturing, construction, maintenance, and disposal. Reinforced concrete is a material imbued with a high level of embodied energy. When producing the cement, sizable quantities of CO2 are emitted in the calcination stage, where limestone becomes calcium oxide (quicklime), as well as through the furnace burning of fossil fuels. If we also consider the exploitation of sand and stone, the use of iron for the rebar, its journey to the construction site to be placed in the mix, we can comprehend the effect of each project phase on the environment. Other construction materials, like ceramic, brick, and plastic, need sizable quantities of energy to be produced since the minerals contained within them must be extracted and treated through energy-intensive processes.
Dual varieties of carbon emissions exist in buildings: Embodied Carbon and Operational Carbon. The second references all carbon dioxide released during the life cycle of the whole building, as opposed to simply its materials, including electricity consumption, heating, cooling, etc.
Comprehending the degree of energy or carbon contained in building materials is integral to the development of eco-conscious projects. Something considered a ‘sustainable material’ in one locale might carry a high energy load in a second, this owing to local availability and the variety of transport in question.
A standardised way to quantify the eco impact of buildings, from material extraction and the production of products to the culmination of their functional life cycle and disposal, is the Life Cycle Assessment. With the use of a quantitative method, numerical results are attained that reflect impact categories and supply comparisons between products that are alike. Similarly, the University of Bath (UK) has put together a list comparing the specific energy quotients contained within the world’s most frequently used materials.
Other tools and technologies promise to make this process possible. Autodesk, along with the Carbon Leadership Forum and other construction and software companies, has created the Embedded Carbon in Construction Calculator (EC3) tool, available to beta users. The tool supplies users with the info needed to make educated determinations regarding the embodied carbon of each element of a structure, promoting sound and workable solutions for the layperson. As with all things, awareness of one’s options is always the key.