The GB Code, a Referral Code of the National Building Code (Presidential Decree No. 1096) was launched on June 25 this year by the Department of Public Works and Highways (DPWH), with the assistance of the World Bank-IFC, and the technical support of the Philippine Green Building Initiative (PGBI). The latter is composed of accredited professional organizations in the building industry.
Here are excerpts of the GB Code:
The general provisions of the Code provide for the protection of the people from the harmful effects of climate change. The Code seeks to improve the efficiency of building performance through a framework of standards that will enhance sound environmental and resource management to counter harmful gases, throughout the building’s life cycle, including efficient use of materials, site selection, planning, design, construction, use, occupancy, operation and maintenance, without significant increase in cost.
The technical professionals, developers, contractors, property managers and building owners involved in the planning, design, construction and management of buildings have the opportunity and the responsibility to help the government address the adverse effects of climate change by ensuring that buildings are planned, designed, constructed, operated and maintained to the required efficiency levels.
Resources must be used efficiently to equitably meet the developmental and environmental needs of the present and future generations.
Occupants of green buildings will benefit from improved indoor environmental quality, which promises higher productivity and better comfort.
The GB Code adopts a staggered or incremental approach and is subject to periodic review of the DPWH secretary through the National Building Code Development Office to modify or include new aspects and emerging efficient technologies and to expand the coverage to other building use/occupancy, or to replace outmoded measures.
For a start, the GB Code will apply to all new construction and/or with alteration of buildings with a minimum total gross floor area (TGFA) as follows:
Residential condominium, 20,000 sqm Hotel/resort, 10,000 sqm Educational school, 10,000 sqm Institutional hospital, 10,000 sqm Business office, 10,000 sqm Mercantile mall, 15,000 sqm Mixed occupancy, 10,000 sqm
The Code does not apply to buildings of the above use/occupancy classification constructed before its effectivity.
When alterations, additions, conversions and renovations of existing buildings constructed after the effectivity of the Code fit with the minimum TGFA above, the whole building shall be subject to the applicable provisions of the GB Code.
Cut down energy use
Since half of the energy bill goes to air-conditioning, buildings with air-conditioning systems will be required to adopt efficient practices, designs, methods and technologies to cut down energy use.
Glass transfers more heat, so the amount of glazing is ideally reduced with respect to the wall size to bring down heat gain inside the building.
The required wall-to-window ratio or WWR needs to be balanced with the amount of daylight coming through the glazed area.
Solar heat gain coefficient or SHGC will be determined by dividing the amount of solar heat passing through the glass by the total solar radiation incident on the glass. The higher the WWR, the lower SHGC required in glass windows.
Visible light transmittance (VLT) will be used to determine the amount of light transmitted through the glass.
Natural ventilation to ensure free cooling and fresh air will be provided by the computation of size of operable window openings to floor area of at least 10 percent.
Roof insulation will be a must, and in amounts corresponding to the roof color. White roofs have a solar reflectance index (SRI) of 92, while dark colors have an SRI of 0-33. Mechanical systems, especially the cooling systems or chillers of large buildings, will have to meet minimum efficiency requirements.
Daylight-controlled lighting systems include photoelectric sensors connected to luminaries which help to dim or switch lamps when there is sufficient daylight.
Efficient water fixtures will be used to comply with maximum water flow rates of different fixtures. Rainwater harvesting from roofs and hardscape is a must for nonpotable use. Nontoxic building materials are those without hazardous effects on building occupants. They will be checked for volatile organic compounds or VOCs, which should be within tolerable levels.
A materials recovery facility will be required for the collection and segregation of solid waste. Hospitals will be required to have isolated bins for hazardous wastes.
Indoor environmental quality standards will require strict adoption of efficient design and operation practices to protect building occupants’ health, productivity and safety. The Tobacco Regulations Act restricts tobacco smoking in public spaces and the prescription of designated smoking areas inside buildings.
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