Green architecture is defined as the style and science of design and construction of buildings in accordance with environmentally friendly principles. Green architecture is the design of buildings that maximizes the benefits available from the immediate natural environment, while minimizing environmental pollution, water and energy consumption. To meet this requirements, green buildings use a number of interventions such as passive solar orientation, shadings, green roofs, green spaces and vertical wall planting systems to maximize on heat, water consumption and cooling efficiency.

 Importance of green architecture

There are a number of features which can make a building ‘green’. These include: 

• Efficient use of energy, water and other resources
• Use of renewable energy, such as solar energy
• Pollution and waste reduction measures, and the enabling of re-use and recycling
• Good indoor environmental air quality
• Use of materials that are non-toxic, ethical and sustainable
• Consideration of the environment in design, construction and operation
• Consideration of the quality of life of occupants in design, construction and operation
• A design that enables adaptation to a changing environment(About Green Building, 2021)

Some of the largest carbon footprints on the terrestrial sphere are buildings. The life cycle of a building generates most carbon at the construction and operation phases. For example, during construction, building materials can be sourced in an unsustainable manner, therefore contributing to transport emissions. At the operation phase, the use of electrical and lighting appliances causes a rise in greenhouse gas emissions. This is because most of the energy consumed on affiliated Heating, Ventilation, and Air Conditioning (HVAC) appliances occurs during the day, where work efficiency is most required. To provide optimum, conducive, or at least bearable working conditions, these appliances are turned on and their peak usage is at certain hours of the day. The cumulative effect is an increased load on main-grid power utilities which use fossil fuels as part of their energy source.  

Green buildings solve the problem of excessive heat and energy costs by incorporating designs that maximize on energy efficiency, water reuse and natural ventilation. Green roofs and green spaces diffuse backscatter radiation by cooling the ambient air at the rooftop and at ground level respectively. Where green spaces are located within the building enclave, they improve air quality and modify the microclimate, thus reducing the reliance on artificial air ventilation. But what about the urban heat island problem? Green architects prefer designs that minimize backscatter radiation, such as external shade systems. An example is the bris-soleil system. These external shades break incoming insolation into different angles, thus preventing large amounts of shortwave radiation—the principal cause of heat—from getting into a room.  The reflected radiation (including from the glass window) is split into different angles, thus minimizing the focus of heat rays to a particular direction.  This reduces the build-up of heat in the streets below which are also notorious high heat absorbers.

The use of green architecture also reduces energy and water consumption costs. Roofs can be designed to support several solar panels and where possible, even small wind turbines. Gutters are traditionally used to collect surface run-off from roofs. Though this is the most convenient water harvesting method, a green architectural signature is a building whose exterior is curved to channel water to a central collection pond. Other tricks up the architect’s sleeves are use of non-traditional materials such as glass and plastics, to serve the same purpose as cement. Creativity and a knack for design are key here.

Considering the benefits that green architecture provides over traditional designs, it ought to be mimicked in every infrastructural design. As we strive to implement the Paris Agreement  (to mitigate climate change) in all facets of the environment, green architecture should be taken up by and even become mandatory in all jurisdictions.  In Kenya, we have organisations such as the Kenya Green Building Society, a non profit non-political, member-based organisation formed to lead the transformation of the built environment in Kenya toward environmentally sustainable buildings, promoting a healthy and efficient built environment.

References

About Green Building. (2021, 06 24). Retrieved from World Green Building Council: https://www.worldgbc.org/what-green-building

American Institute of Architects (AIA). (2019, April 23). Top 10 green buildings for 2019. Retrieved from Building design+construction: https://www.bdcnetwork.com/cote/top10/2019