Considering that almost half of the world’s population lives in urban areas, cities are facing greater challenges by the day in managing and curbing their impact on the environment. The rapid rate of urbanization and exponential increase in the size of urban areas contributes greatly to climatic differences between urban and rural areas - meaning simply, that urban areas are contributing greatly to global warming by getting warmer.
The phenomenon of the rise in temperature in urbanized zones is known as the Urban Heat Island. Cities are getting warmer and warmer, mainly because the synthetic, man-made materials that are replacing natural vegetation in these zones is absorbing much of the natural radiation, which is then released as heat.
For climates that already experience high levels of humidity, the urban heat island can contribute to a harsher environment in which to live. It is of vital importance that close attention is paid to the monitoring of temperature rises in these zones, particularly as Asian cities continue to grow in large numbers.
The building envelope
The building envelope is essentially the thermal barrier between the interior and exterior of the building that creates the conditions necessary for thermal comfort within the building. It is also part of the determining factors for how much energy is needed to heat and cool a building. In the cause of reducing the urban heat island and lessening the environmental impacts of the building, it is necessary to consider design elements that will enable the building to create a cooler building envelope and thus radiate less heat into the surrounding environment.
Green building solutions for curbing the UHI effect
Implementing sustainable design elements into your building will not only help your building to achieve green building certification standards and align with energy efficiency goals; it will also help to curtail your building’s effect on climate change and global warming.
There are many different considerations for sustainable design that can be implemented in your building to achieve this. In hot and humid climates, using reflective roofing and reflective walls can help as they reflect more sunlight in the natural evaporation cycle - and absorb less heat.
Restricting the passage of air through the building, particularly in humid climates, can also help to increase energy efficiency by reducing the demand for latent heat load reduction and cooling. This will also eventually help to manage your building’s heat transfer and to lessen its impact on the urban heat island effect.
There is also the possibility of a symbiotic relationship between your building and the environment, as the green building landscape of the city in which your building is built will also influence your building’s energy consumption needs. For example, it has been found that surface temperature of buildings can drop considerably when neighboring buildings are fitted with bio-inspired retro-reflective facades.
With roughly a third of the world’s energy needs consumed by buildings alone, it is pivotal time to consider the impact that your building has on climate change and global warming. Aiming towards a green building by considering sustainable design elements, particularly ones that contribute to a cooler building envelope, can reduce your building’s contribution to the urban heat island and ultimately curb its effect on global warming.