DISCUSSION
Green Building, what it is, the benefits and the business case
1. What is ‘Green’ Building?
Whilst there are number of definitions, the generic statement implies that a “Green Building” is a building that, in its design, construction or operation, reduces or eliminates negative environmental impacts, and can create positive impacts, on our climate and natural environment, preserve dwindling natural resources and improve our quality of life (World Green Building Council Report 2019).
As related to the Sustainable Development Goals defined by the UN, the green building sector provde a number of beneficial effects. These range from improvement of health & wellbeing, use of renewable of energy with
lower associated running costs, creation of jobs and boost for economies, spurring of innovation and contributing to climate resilience, providing sustainable communities and better living, using circular economy principles where resources aren’t wasted, production of less emissions to combat climate change, and contribute towards helping improve biodiversity & save water resources.
The economic and social benefits of green building include delivering on economic priorities including return on investment and risk mitigation and on social priorities such as employee productivity and health (WGBC 2019).
The business side - economically, for developers through to owners and tenants, are also proven to be beneficial across the board. A 2013 WGBC Report researched a number of sectors and the benefits were as follows.
Developers discovered that building a ‘green’ building’ was far cheaper than expected; that higher sales prices were commanded, and that tenants and prospective buyers alike were prepared to pay a little extra for the benefits - and kudos - of living in or owning, a 'green’ property. On the commercial aspect, a higher corporate prestige value was incorporated, with less running costs and happier tenants and/or more productive workers due to the beneficial aspects of more light, better air quality and thermal comfort.
“New large developments should be subject to mandatory rigorous assessment...”
—Sant & Borg, 2014
2. An upwards trend
As the demand for more sustainable building options increases, green construction has become increasingly profitable and desirable within the global construction market. The green building market is anticipated to be among the fastest growing industries worldwide.
The number of LEED-certified projects in the United States rose from 296 certifications in 2006 up to over 67,200 in 2018 (Wang, 2019).
Whilst LEED statistics may not seem to be applicable to Malta as a European state, it is also undeniable that the global trend for ‘green’ construction is on the up as witnessed by the chart on the right, taken from a leading statistics company.
Energy consumption has dramatically increased in buildings over the past decade due to population growth, more time spent indoors, increased demand for building functions and indoor environmental quality, and global climate change. Building energy use currently accounts for over 40% of total primary energy consumption in the U.S. and E.U. (Cao et al 2016).
Significant energy savings can be achieved in buildings if they are properly designed, constructed and operated. For this reason, building energy efficiency can provide key solutions to energy shortages, carbon dioxide emissions and their serious threat to our living environment. The time has never been more pressing for the introduction of and legislation pressing for mandatory green building standards.
3. A Substitute for cement…
The cement industry equates to an estimated 8 percent of global carbon dioxide (CO2) emissions. It produces a material so ubiquitous it is nearly invisible: cement. It is the primary ingredient in concrete, which in turn forms the foundations and structures of the buildings we live and work in, and the roads and bridges we drive on. Concrete is the second most consumed substance on Earth after water. And a lot of water in turn is utilised to make concrete.
Cement is indispensable for construction activity, so it is tightly linked to the global economy. Its production is growing by 2.5 percent annually, and is expected to rise from 2.55 billion tons in 2006 to 3.7-4.4 billion tons by 2050
Manufacture of Cement
Though “cement” and “concrete” are often used interchangeably, concrete is actually the final product made from cement. The primary component of cement is limestone. To produce cement, limestone and other clay-like materials are heated in a kiln at 1400°C and then ground to form a lumpy, solid substance called clinker; clinker is then combined with gypsum to form cement.
Cement manufacturing is highly energy- and emissions-intensive because of the extreme heat required to produce it. Producing a ton of cement requires 4.7 million BTU of energy, equivalent to about 400 pounds of coal, and generates nearly a ton of CO2. Given its high emissions and critical importance to society, cement is an obvious place to look to reduce greenhouse gas emissions.
Cement Emissions
The production of cement releases greenhouse gas emissions both directly and indirectly: the heating of limestone releases CO2 directly, while the burning of fossil fuels to heat the kiln indirectly results in CO2 emissions.
The direct emissions of cement occur through a chemical process called calcination. Calcination occurs when limestone, which is made of calcium carbonate, is heated, breaking down into calcium oxide and CO2. This process accounts for ~50 percent of all emissions from cement production.
Indirect emissions are produced by burning fossil fuels to heat the kiln. Kilns are usually heated by coal, natural gas, or oil, and the combustion of these fuels produces additional CO2 emissions, just as they would in producing electricity. This represents around 40 percent of cement emissions. Finally, the electricity used to power additional plant machinery, and the final transportation of cement, represents another source of indirect emissions and account for 5-10 percent of the industry’s emissions.
Is there a solution?
Development of new concrete additives could produce a stronger, more workable material whilst reducing the amount of cement required and the resulting CO2 emissions. Currently, the air quality of Malta is being significantly effected by the extensive production and use of cement and concrete. New substitutions need to be found before air quality reduces further.
This article has been adapted from an original article (Rubenstein 2012). Please see here for original article