Is your house safe from earthquakes? Here's a 12-point guide for you to know

Evaluating how safe your home is from damage due to earthquakes is now right at your fingertips.

The mobile version of the "How Safe is My House? Self-Check for Earthquake Safety of Concrete Hollow Block (CHB) House in the Philippines" provides a simple and easy-to-use tool for owners and occupants to check the safety of residential houses and other one- to two-storey CHB buildings, the Philippine Institute of Volcanology and Seismology (Phivolcs) said during its launch on Tuesday, April 13.

The app can be downloaded for free on Google Play Store or through tiny.cc/HSIMH.

"By answering 12 questions, Android users can evaluate the safety of their CHB houses, and understand its likely vulnerability to a strong earthquake," Phivolcs said in a statement on Thursday, April 15.

The self-check guide questions are the following:

Who built or designed my house? This question refers to the person who supervised the building of the house.

A. Built or designed by a licensed civil engineer/architect.

B. Not built by a licensed civil engineer/architect.

C. It is not clear or unknown.

How old is my house? This checks if your house was built under more recent earthquake-resistant building standards.

A. Built in or after 1992.

B. Built before 1992.

C. It is not clear or unknown.

Has my house been damaged by past earthquake or disasters? This checks if the house sustained structural damage and had undergone repair works.

A. No or Yes but repaired.

B. Yes but not yet repaired.

C. It is not clear or unknown.

What is the shape of my house? This checks the shape of your house, which influences behavior during strong ground shaking.

A. Regular (symmetrical, rectangular, box-type, simple)

B. Irregular/complicated

C. It is not clear or unknown

Has my house been extended or expanded? This checks if additional construction was properly executed and correctly attached to the original structure.

A. No or Yes but supervised by a civil engineer/architect.

B. Yes but not supervised by a civil engineer/architect.

C. It is not clear or unknown.

Are the external walls of my house six-inch (150-mm) thick CHB? This checks if the standard size of at least six-inch thick CHB was used.

A. Yes, it is six inches.

B. No, it is thinner than six inches.

C. It is not clear or unknown.

Are steel bars of standard size and spacing use in walls? This checks if the standard size and spacing of steel bars were used as reinforcement.

A. Yes (10 mm diameter, tied, and spaced correctly)

B. No, fewer and smaller than 10 mm.

C. It is not clear or unknown.

Are there unsupported walls more than three meters wide? This checks if the wall is properly supported from falling down.

A. None, all unsupported walls are less than three meters wide.

B. Yes, at least one supported wall is more than three meters wide.

C. It is not clear or unknown.

What is the gable of my house made of? This checks if the gable wall is properly supported by sufficient steel bars or by a lintel beam.

A. Light materials, properly anchored CHBs, no gable wall.

B. Not properly anchored CHBs, bricks, stone.

C. It is not clear or unknown.

What is the foundation of my house? This checks if the foundation is properly constructed to support the walls.

A. Reinforced concrete.

B. Stones or unreinforced concrete.

C. It is not clear or unknown.

What is the soil condition under my house? This checks if the house was built over a stable or stabilized ground.

A. Hard (rock or stiff soil)

B. Soft (muddy or reclaimed)

C. It is not clear or unknown.

What is the overall condition of the house? This describes the overall physical state of the house and checks defects or any deterioration.

A. Good condition

B. Poor condition

C. It is not clear or unknown.

"The result determines if the structure is safe and presumably built according to standard construction procedures. If not, it may recommend further professional consultations and necessary structural strengthening," Phivolcs pointed out.

The "How Safe is My House?" mobile app is adapted from the 2014 print information material, which was a major output of the collaborative project with the National Research Institute for Earth Science and Disaster Prevention, Japan International Cooperation Agency, Japan Science and Technology, and the Association of Structural Engineers of the Philippines.

The development of the How Safe is My House app is one of Phivolcs' initiative to increase Filipinos' awareness on proper construction practices and standard design, and highlight the importance of structural integrity in building safer and resilient communities.

A web-based version and Filipino translation will also be made available soon to stakeholders via multiple channels, it added.

"Through this mobile application, DOST-Phivolcs aims to reach out to as many Filipinos as possible, making the diagnosis of CHB houses quick and easy. It is envisioned that through this innovation, people would be more conscious of the need to construct seismically-sound structures," Phivolcs said.