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You need just one full day on the road to find out that Metro Manila struggles with traffic woes and lost time. This megalopolis has a daytime population of almost 13 million people, and is one of the highly urbanized centers of the world. With its 16 cities and one municipality, Metro Manila is expected to expand its borders even further as a result of rapid urbanization, to include parts of Bulacan to the north and parts of Laguna to the south. According to the World Urbanization Prospects Study of the United Nations, Metro Manila has an annual rate of change of urbanization of over 2%, more than its Southeast Asian neighbors, and this will continue until year 2050. This is due in part to a 40-70% increase in urban population that overtakes that of the rest of the Southeast Asian region and the world. Off hand, one can imagine the creeping transformation of the natural landscape from pristine foliage and vast and breezy spaces to a jungle of concrete, asphalt, and glass; not to mention overcrowding, heat, and pollution.

Since skyscrapers dominate the metropolitan skyline, site sustainability becomes a necessity. Site sustainability is the practice of maintaining and building outdoor spaces that will allow the protection and enhancement of site ecology and the continuation of biodiversity to an acceptable degree. Though highly urbanized centers will have limited opportunities to maintain undisturbed open spaces, site sustainability will allow for various ways of coping, and making the city livable. Some of the ways are: protection of surrounding environs from the activities of the built-site, recharging of underground aquifers, maintenance of vegetated open spaces that can reduce urban heat island effect, and visual connectivity between building indoors and outdoors.


Site protection allows the site and its surrounding environment to be protected, and preserves much of its natural characteristics. This includes protection against land erosion, which can be caused by unprotected and exposed land features, and stormwater run-off. Especially during building construction activities where land is disturbed, various strategies such as earth dikes, sedimentation pond, mulching, seeding, and other techniques that can stabilize the land surface and manage stormwater run-off can be applied.


Natural or developed sites with permeable land surfaces through vegetated cover, soil, gravel or porous paving materials will allow the percolation of rainwater into the ground. This is important in sustaining the supply of freshwater for the population. Permeable land surfaces, and especially with heavy foliage, will slow down the run-off of storm water to road and storm drainage networks. This will help reduce flooding.


Vegetated sites can also control the built-environment’s microclimate. This can help reduce the cooling needs of the building and attain energy efficiency. Trees and plants also absorb carbon dioxide and in the process, produce oxygen that can help sustain good air quality.


Maintaining views, open and vegetated outdoor spaces and applying visual portals and corridors from inside the buildings can enhance building occupant health and well-being. Studies have shown that workers, students, and hospital patients perform and recover better and faster if there is a visual connection to the outside.

Another aspect of site sustainability is the rational allocation and preservation of land resources for various land uses, with importance given to maintaining land resource for food production and water retention. Sustainable sites will slow down the intrusion of built-spaces into remaining open spaces, enhance the quality of life, and reduce greenhouse gas emissions, especially with the introduction of walkable communities and sustainable transportation.


With all basic services within easy reach of the urban dweller, walkable communities, or planned unit developments (PUD) will mean encouraging walking, using bicycles, and reducing motor vehicular use. This will realize reduction in energy consumption, fuel, and greenhouse gas emissions. Mixed-use developments are walkable communities where almost everything: places of work, living, services and recreation are within reach from each other. This can also enhance the physiological welfare of people as social connectivity is achieved.

Walkable communities will also mean that basic services such as electricity, water, and other utilities are easily distributed within a limited area and will enhance efficiency in energy use and delivery.


The objective of sustainable transportation is to reduce the use of private motor vehicles, and subsequently, reduce energy use and greenhouse gas emissions due to transportation. The hierarchal use of mass transportation — such as rapid railways for regional travel, mono or light railways for inter-city commute, and shuttles within a city — is an efficient way of transporting commuters no matter the distance. Plus, the use of bicycles and even walking are easily encouraged in traveling within districts or neighborhoods. But the most effective way of sustainable transportation is telecommuting. This involves just the use of the Internet to allow tele and video connectivity between people despite the distance. This way, resources used are almost negligible, time is not lost, and productivity is made efficient. When these sustainable practices are applied, the environment is protected, resource-use is made rational and sustainable, GHG emissions are reduced and the sociocultural aspect of any community is preserved and enhanced.

Emelito C. Punsalan is vice-president for technical affairs of the Philippine Green Building Initiative. He is an accredited PGBI-GREEEN assessor and EDGE certifier for voluntary green building certification systems. He is also a partner of LR Punsalan & Associates.

Republished from Green Breakthroughs by Emelito C. Punsalan| Business World – Property Section, February 21, 2017 


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