‘Green’ buildings to help mitigate effects of floods
Green buildings, green roofs and green walls. These are architectural and engineering strategies that the country needs to adopt in order to mitigate the impact of storms and floods, according to former senator and Environment Secretary Heherson Alvarez.
By “green building,” Alvarez means an efficient and environmentally-friendly building that uses a minimum of energy. Glazed solar or wind panels can be installed to minimize the use of electricity and air conditioning.
A “green roof” is a rooftop garden or rain garden, that is partially covered with plants. It is equipped with a drainage and irrigation system that can store a large amount of water that can be recycled to flush toilets or do the laundry. The roof also improves the quality of air by filtering off dust particles, pollutants and carbon dioxide.
A “green wall” has plants vertically planted to absorb the heat. Both the green roof and the green wall reduce surface runoff.
Next to transport, buildings account for 30 to 40 percent of global energy usage and greenhouse emissions, Alvarez cited.
With climate change and disastrous calamities, green planning needs to be given a bigger push, said Alvarez
Christopher de la Cruz, an architect and president of the Philippine Green Building Council (PhilGBC), a Filipino nonstock corporation that promotes green initiatives, said green building technology has long been known. “However, we tend to forget some of the time-tested ideas in construction. We need to revisit them,” he said.
“With rapid urbanization and in the name of progress, we kept on building and building to the point that we exceeded our carrying capacity,” de la Cruz said.
“If you look at the old city plans, they had identified flood zones but for some reasons, they are being converted into building zones.”
One way to address flooding, he said, is to build reservoirs that essentially hold and store water for future use.
“Houses should have green roofs. That is already being done here but it would be better if all people are doing it,” de la Cruz said.
De la Cruz said green materials, when integrated in building design, complement existing drainage.
He said environmental damage should no longer be viewed as a trade off for economic expansion.
De la Cruz, who drafted the green guide for socialized housing for the National Housing Authority, said efforts should be made to make surfaces permeable, and to require landscapers to use local plants which require less water and pesticides.
Benefits to the poor
The poor, who are the most affected by calamities, can benefit from green initiatives once adopted throughout the country because of the savings that can be generated by the government from reduced energy consumption. These savings can be channeled to expanding basic services, Alvarez said.
Quezon City already gives incentives to green projects through a city council ordinance.
Rogelio SP Lim, president of the Philippine Constructors Association-Metropolitan Chapter, said local government and community support are needed to make green policies sustainable.
“National policies that will protect the environment will not be effective without the local support,” Lim said.
He said businessmen like him could do their part by converting their offices into green spaces.
Lim is the owner and developer of Boni Tower, the first registered BERDE building in Mandaluyong City and among the first five in the Philippines. The BERDE Green Building Rating System (BERDE) is a PhilGBC program.
For existing old or “dinosaur” public buildings, Alvarez proposed they be retrofitted to meet the green standards.
In Congress, some green measures are being introduced.
Senator Ferdinand “Bongbong” Marcos has filed a bill that seeks to bring the Philippines up to global standards in sustainable buildings and construction developments.
Senator Miriam Defensor-Santiago and Aurora Representative Juan Edgardo “Sonny” Angara are both espousing green education in schools.
A bill filed by Representative Anna Bondoc seeks to convert the Batasang Pambansa complex, home of the House of Representatives, in Quezon City to a green building.
Angara said structures that help conserve or optimize energy use, or which are efficient in disposing of wastes must be encouraged.
“Given the situation where there is a water and power shortage and we are constantly battered by storns and calamities, a high value must be placed on coping with climate change in an optimal manner,” Angara said. “Structures which help conserve or optimize energy use, or which are efficient in disposing of waste do deserved to be encouraged.”
Alvarez criticized what he said was a predominantly adaptive public works solution to natural calamities.
A P2.2-billion engineering solution announced by President Benigno Aquino at the height of the heavy rains and flooding in the metropolis two weeks ago primarily involves the construction of a dike along the Meycauayan River to ease the inundation of Malabon, Valenzuela, Navotas and Bulacan and the construction of retarding basins and embankments along the Marikina river.
Alvarez said similar dikes and much longer drainage systems built in Pampanga during the administration of President Gloria Macapagal-Arroyo proved ineffective in past typhoons, with the dikes breaching their holding capacity and ability to divert water fast to the sea.
“Adaptation is pure building public works. Pero mali iyan (That’s wrong). These (dikes) are not adequate without meteorological understanding or a solution to bring down the carbon dioxide impact,” Alvarez said.
“The impact of global warming will come so sudden, so swift and very destructive that whatever adaptation programs you have, these will be rendred useless. There should really be a mitigation measure understood by the local and world communities,” he stressed.
Alvarez cited findings of the Intergovernmental Panel on Climate Change (IPCC) that showed the earth has 50 years to cut the 200-gigatonnes of carbon dioxide in the atmosphere, otherwise the heat will reach the tipping point. In some areas, it is already 1.6 degrees.
“The modules have shown that if the earth warms up by 2 degrees, it may be the point of no return,” Alvarez warned.
He said all countries needed to take climate change seriously and bring down carbon emissions and other toxins that are warming the atmosphere. Otherwise, adaptive structures will simply be swept away by ever increasing climate disasters. A green building policy will help slow down climate change and mitigate its effects, he said.