Are green buildings quake-resistant?

Two subjects are dominating the construction and property circles nowadays—the rising numbers of sustainable, environment-friendly buildings, and the “Big One” (referring to the perceived “overdue” temblor originating from the Marikina Valley fault that can hit Metro Manila anytime).

Thus, the question needs to be asked: Are “green” buildings also designed to be earthquake-resilient? Inquirer Property asked the architects and structural experts.

“A green certification is not necessarily a guarantee of earthquake resilience. We have yet to reconcile and integrate the multiple goals of strength (tibay), resilience (tatag) and sustainability (taguyod),” Benito M. Pacheco, PhD, PE, Apec engineer, and University of the Philippines Diliman College of Engineering professor and vice chancellor for academic affairs, told Inquirer Property in a phone interview.

“Some green approaches do not yet harmonize with earthquake or typhoon resilience; we have yet to reconfirm their mutual harmonization,” he added.

Architect Edgardo Reformado of the Green Architecture Advocacy Philippines stressed that, green or not, the structural integrity of buildings is the responsibility of structural engineers in coordination with the architects who design the buildings. The code for structural design has recently been upgraded to address the “Big One.”

Architect Amado de Jesus, Philippine Green Building Initiative initiator and president, agreed with Reformado’s view. “It is important that a building’s design conforms with the latest National Building and National Structural Code for Buildings of the Philippines.”

Alexis A. Acacio, professor of the UP Institute of Civil Engineering, explained to Inquirer Property that “green buildings focus on the energy efficiency of structures. This includes efficient lighting, ventilation and the optimum use of materials. The earthquake resistance of a building is still determined by the structural engineer. However, it is very much possible for a green building to be highly earthquake resistant.”

Near or far?

Reformado observed: “The usual questions asked by condo buyers are: ‘Is this designed to withstand a strong quake?’ ‘Is this near or far from the fault line?’ For an earlier-built building, they would ask, ‘Who was the developer or contractor?’ Seldom do they ask if this is green building. I hope they do. We at Green AP encourage buyers and developers to go green, because such projects are healthier to live in and even perform better financially. Reports on sustainable buildings say ‘What’s good for the environment is good for business.’”

He added, “I think some LGUs are requiring building owners to review the structural stability of their buildings to conform to the new code and perform some retrofitting, and hopefully continue to renovate and convert these into energy-efficient and sustainable buildings.

‘Tibay, tatag, taguyod’

In his statement during a three-day conference last November on “Sustainable Buildings, Infrastructures and Communities in Emerging Economies” in Quezon City, Pacheco stressed the essential qualities of tibay, tatag and taguyod.

“We need to be able to build back better, to have resilience. However, we do not have infinite resources. So our higher challenge is sustainability. While we are keeping stronger and staying resilient, we are mindful and careful that our generation is able to do so while promoting the chances of generations to come,” he said.

Guide questions

In March 2010, Inquirer Property published 16 critical questions building occupants must ask builders and engineers:

• Is the building’s documentation clean? Corruption and building integrity don’t mix.

• Did you study the lay of the land? Geotechnical studies prior to building are a must.

• Did you (the engineer) “read between the (fault) lines”?

• Were you faithful to the blueprint?

• Were you faithful to the National Structural Code of the Philippines?

• Did you account for the gravity and lateral loads?

• Did you (the engineer) ensure that the building’s structural members are seismic-resistant?

• Did you keep your eyes straight and align the building’s structure? The vertical and horizontal alignments of structural framing of the building must be maintained.

• Did you check the neighboring structures? Your new building might be safe and sound, but can you say the same for the old one beside it?

• Has the building been routinely inspected by the city engineer’s office?

• Are the cracks seen in the house superficial, or serious?

• Is the building at its maximum tolerable stage?

• Did the builders do shortcuts to lessen costs?

• Is the building making snapping or cracking sounds lately?

• Is the building perfectly perpendicular to the ground?

• Has this building’s reinforcements gone over the top, or is this building overreinforced?