By 2015, the sector was estimated to consume about 32% of all energy used in the world. Consequently, it was responsible for about 19% of all emissions of greenhouse gases globally at the time. In the United States, for instance, the real-estate and construction sector alone was responsible for about 40% of all national energy consumption and about 35% of all greenhouse gas emissions. Greenhouse gases affect the global climate and, therefore, the biosphere in an adverse way. These gases increase the global temperatures, melt the Polar Ice, and contribute to the rising of sea levels, and so forth.
Nonetheless, greenhouse gases can be reduced and their effects alleviated and the building and construction sector can be a major contributor to this objective. In fact, it is possible now with today’s technology to achieve 50% to 90% energy savings in this sector.
By opting for green buildings rather than conventional buildings, the contribution of the real estate and construction sector to greenhouse gas emissions can be greatly reduced.
Green buildings are healthy, environmentally-friendly facilities designed and constructed in a way that is resource efficient. That said, this definition of green buildings lays too much emphasis on the environmental effect of the building and too little on how the buildings affect those who inhabit and interact with them. Green buildings in their truest sense offer optimal utility to their inhabitants, use minimal natural resources, while at the same time affecting the environment and by extension the biosphere as less as possible. This paper examines the evolution of green buildings and the emerging trends in the sector.
While green buildings have become more common in the last 10 years, their origins can be traced as back as the late 1800s. Systems like, ambient lighting, underground air cooling systems, roof ventilators, and many more have been in existence for at least a century. Buildings like the New York Times Building in the United States have, for instance, used deep-set windows among other systems to regulate their internal temperature and to reduce their impact on the environment since the early 1900s at least. However, with the advent of heating, ventilation and air conditioning (HVAC) systems in the 1930s, these progressive cooling systems lost their steam and were all but supplanted by these new HVAC systems; a development which altered the building sector significantly and for a very long time.
The entry of HVACs, structural steel, and reflective glass into the building industry made the steel and glass buildings that dominate many American cities today very popular. These new types of buildings could be cooled and heated with huge HVAC systems that used massive quantities of inexpensive and easily available fossil fuels. The buildings were, therefore, viable for as longs as cheap fossil fuels were readily available. In the 70s, however, a group of progressive architects, ecologists, and environmentalists inspired by the environmental movement and high oil prices of that time reinvigorated the green buildings movement. These two events, that is, high fuel prices and the environmental movement of 1970 played a critical role in the birth of the modern green build movement.
The First Earth Day marked on 22nd April 1970 gave the movement some credibility but high fuel prices and fuel shortages of 1973 gave the environmental movement and by extension the green build concept the impetus it needed. With gas queues extending for miles, people started to have their doubts about conventional fuel sources and particularly fossil fuels as the only sources of energy. The fuel shortages abated eventually and was expected slowed down the green build movement, nevertheless, a small group of dedicated architects, engineers, and other professionals in the real estate and construction sector continued to push for the adoption of green buildings. For example, the Gregory Bateson Building in Sacramento California used ideas such as green cooling systems, solar cells, and so forth; and the Willis Faber and Dumas building in the United Kingdom used ideas such as mirrored windows, ambient lighting, grass roofing, and so forth.
In the late 70s right through the 80s up to the early 90s, a lot of research was done on green and energy efficient systems. This research yielded better water recovery processes, green wall systems, efficient solar panels, and better ambient lighting systems, which reduced daytime energy use. Perhaps, the most significant time for the green build movement is when Bill Clinton became the President of the United States in 1992, the green movement was to popularize the idea to average Americans, proposed the greening of the White House. Two decades after the First Earth Day, President Clinton, approved the project to make the White House energy efficient and environmentally friendly. After only two years, the project had managed to save the White House more than $300, 000 in the way of water, energy, landscaping, and waste management costs. Since 1997, an average of $300,000 has been saved annually courtesy of additional greening projects on the White House.
After all the years of green buildings adoption, the real-estate and construction sector still contributes considerably to environmental destruction. Recent research shows that the building and construction sector still consumes about 15% of global clean water resources; about 40% of the world’s energy; and still contributes about 30% of all greenhouse gas emissions. In addition to that, the global market for buildings is predicted to grow at a compound annual growth rate (CAGR) of about 9% from 2016 to 2020. To avoid the negative impacts of climate change and to reduce other harmful effects of environmental degradation; it is imperative to tackle the effects that buildings have on the environment. Energy efficiency and decreasing the impact that buildings and construction materials have on the environment is one of the best approaches to reduce people’s impact on the biosphere and environment in general.
The demand for green buildings has been on the increase globally; so much so, that the global market for green buildings is now worth about $1 trillion and is projected to grow even more in the coming years. For that reason, the current practices in green buildings is to build houses that are affordable, comfortable, and attractive; houses that do not destroy the environment or the biosphere in their construction, use, or deconstruction. That said, the main four objectives of many green builders in 2018 are first to minimize the effects that buildings and building materials have on the environment. Secondly, the environmental impacts because of occupancy of buildings should be reduced. Thirdly, the impacts that the buildings have on the environment at the end of their life should be limited. And lastly, the movement aims to optimize the human experience of buildings, that is, ensure that buildings enhance the health, comfort, and the wellbeing of not only those who inhabit them but those who live close or around them.
Green buildings are renowned for energy efficiency and low or zero greenhouse emissions. Another common practice currently is to construct buildings that leverage on these aspects of green buildings to benefit communities in the way of not drawing too much from the local infrastructure or local amenities like water, electricity and so forth. Until now, green buildings have aimed to be sustainable through energy efficiency and through reduction of greenhouse gas emissions. Future green buildings, however, will incorporate other strategies like innovative green building materials, green roofs, retrofitting buildings that are not yet green, and so forth. Retrofitting generally entails refurbishing or upgrading conventional buildings to the level of green buildings concerning energy consumption, energy efficiency, user experience, impact on the environment and so forth.
Mostly, it entails implementation of energy-efficient systems. In many cases, it involves replacing traditional HVACs with smart HVAC systems, reducing energy consumption through substituting conventional incandescent lighting with compact fluorescent lamp (CFLs), and so forth. Living roofs is another trend that is likely to take off soon. Living roofs are also called green roofs. A building whose roof is partly or completely covered with either soil or vegetation is said to have a living or green roof. These kinds of roofs have many benefits, they help the building blend well into the environment, and plants on the building absorb carbon dioxide and release oxygen thereby providing climate stabilization. In addition to that, living roofs minimize rainwater runoffs, block or absorb pollutants in the air, provide habitats for birds, animals, and so forth; they also help reduce heating and cooling costs just to name a few benefits. In fact, research shows that if only 8% of all roofs in the city were to be made green, the ambient temperatures in the city would reduce by as much as 5 degrees Fahrenheit.
Because of the ever-increasing effects of climate change, all human activities soon may have to be carbon neutral. For the real-estate and construction sector, this will mean a move towards buildings that are completely carbon neutral. In fact, some countries like the United Kingdom (UK) had already taken steps to ensure that all new buildings in the future will be carbon neutral. Per this plan, all new homes built in the UK after 2016 were required by law to aim at adding zero carbon into the environment over the course of a year. That is, all homes built after 2016 had to find a way of ensuring that all emissions from heating, cooling, ventilation, lighting, hot water, waste disposal, and so forth met the zero carbon home requirements set by the government.
Another emerging trend in green buildings is that of cradle-to-cradle design; this concept aims to design houses or buildings, systems and communities that have overall positive effects on the health of humans and the environment. This concept borrows from the closed-loop nutrient or food cycles in nature. Nutrient cycles in nature do not have wastes, the current conventional building designs can be considered cradle-to-grave because building materials are considered a waste management problem. Conversely, the cradle-to-cradle design concept would utilize materials that would biodegrade after use, materials that would even restore soil fertility after use. Ultimately, the future goal is to create buildings that function more like nature itself or trees that is, buildings that capture carbon dioxide, fix nitrogen, distil water, produce oxygen, collect solar energy, improve soils, provide habitat for fauna, change per the seasons, and are aesthetic.
By 2050, the global built area is projected to at least double in size. Accordingly, the global energy consumption is expected to increase by as much as 50% (Abergel, Dean, & Dulac, 2017). The incremental building, that is, building one or a few green buildings at a time, will not be sufficient to capture the green building’s full potential in reducing greenhouse gas emissions. In addition to that, the International Energy Agency (IEA) requires all actors in the building sector to ensure that all emissions caused by buildings are reduced by at least 85% before 2060. All new buildings must, therefore, aim to be carbon neutral; all conventional buildings must be retrofitted with green systems, to make them as green as possible, and all buildings must be integrated or linked electrically and thermally to enhance energy efficiency. Green buildings have already been adopted extensively across the world and their adoption is only expected to grow in future. Globally, the real-estate and the construction industry are to blame for the consumption of a vast amount of energy, water, and other resources. Nonetheless, this sector also has the greatest capacity to deliver considerable reductions in greenhouse gas emissions at a minimal or zero cost.
Buildings in the whole world contribute about 9 billion tons of carbon dioxide every year. Consequently, if green buildings do not become the norm in this period of rapid population and economic growth, greenhouse gas emissions could more than double by 2050. It is worth noting that, merely building a certain fraction of green buildings will not significantly reduce the impact that buildings have on the environment or the biosphere; green buildings must be the standard practice going forward if real progress in protecting the biosphere is to be made. All buildings should move towards real sustainability. For that reason, future green buildings will likely aim not only to reduce the environmental impacts of buildings and improve energy efficiency but also to ensure that building improves user experience, and so forth.