Luxury Living, Shifting Grounds? Seismic Considerations in Merville Park Subdivision

When the Philippine Institute of Volcanology and Seismology (Phivolcs) launched its Seismic Hazard Atlas in late 2024, it gave engineers and homeowners something more precise than general warnings: ground-motion maps that show exactly how the earth is expected to shake in different parts of the country. For anyone living in or considering a home in Merville Park Subdivision, that atlas matters because it turns a vague anxiety about “the Big One” into a specific, addressable question about the soil beneath their lot and the structure above it.

Merville Park sits in a part of Metro Manila where the ground story is more complicated than most buyers realise. The subdivision is not directly on a known fault trace, but proximity to the West Valley Fault system — which Phivolcs has warned is nearing its active phase — means the real risk is not the fault line itself but how the local soil behaves when seismic waves pass through it. That distinction is the difference between a house that sways and one that cracks.

This is not a new conversation for residents of established villages in Pasig and nearby cities. The same questions about structural readiness have come up in Eastwood City and Xavierville Estates, where the gap between what homeowners assume and what engineers measure can be wide. What follows is a look at what the available data and engineering standards actually say about living in Merville Park — not to alarm, but to give residents and prospective buyers a clearer sense of what they are dealing with.

What the Seismic Hazard Atlas Means for Merville Park

The Seismic Hazard Atlas is not a prediction of when an earthquake will happen. It is a tool that tells engineers what forces a building in a given location should be designed to withstand. For Merville Park, the relevant map is the Maximum Considered Earthquake (MCE) map for the National Capital Region, which follows international seismic design standards. A homeowner cannot read these maps directly and conclude “my house is safe” or “my house is not safe” — but a structural engineer can use them to evaluate an existing structure or design a new one with far greater accuracy than the old one-size-fits-all approach.

What makes Merville Park particularly worth examining is its age. Many homes in the subdivision were built decades before the current National Structural Code of the Philippines (NSCP) was adopted, and certainly before performance-based design became common practice. A house built in the 1970s or 1980s may have been perfectly sound by the standards of its time, but those standards did not account for the kind of site-specific seismic data that is now available. The question is not whether the house was built poorly — it is whether it was built for the ground motion that engineers now know the area can expect.

Soil Behavior, Liquefaction, and What It Means for Your Lot

Before any major developer like Ayala Land begins construction, the company commissions detailed geological, geotechnical, and seismic hazard studies that examine soil behavior, bearing capacity, potential liquefaction, and proximity to known fault systems. That level of investigation is standard for a new high-rise project, but it is rarely done for an individual house in an older subdivision. Most homeowners in Merville Park have no idea what kind of soil their foundation sits on, or whether that soil is prone to liquefaction during strong shaking.

Liquefaction occurs when saturated, loose sandy soil loses its strength during an earthquake and behaves like a liquid. Buildings on liquefiable soil can sink, tilt, or float upward as the ground loses its ability to support them. The Phivolcs atlas includes liquefaction hazard maps, and parts of Pasig City — particularly areas near the Marikina River and its tributaries — have been flagged as having moderate to high liquefaction potential. Merville Park is not directly on the river, but the subdivision’s proximity to the Marikina Valley means the soil profile deserves attention.

This is where the gap between luxury expectations and seismic reality becomes most apparent. A beautifully renovated home in Merville Park with marble floors, imported fixtures, and a landscaped garden may look like a safe investment, but none of those finishes matter if the foundation was not designed for the soil conditions beneath it. The engineering principle here is simple: the structure is only as strong as the ground it sits on. No amount of architectural beauty compensates for a foundation that was not built for the site’s actual seismic demand.

What Buyers and Homeowners Commonly Misunderstand

→ Scroll right to see all columns

The Age of the Structure and the Code It Was Built To

The NSCP has been updated several times since the 1970s, with major revisions in 1992, 2001, 2010, 2015, and 2021. Each revision incorporated lessons from earthquakes around the world and improved understanding of how buildings behave under seismic loads. A house in Merville Park built in 1985 was designed to a code that did not require the same level of ductility, reinforcement detailing, or lateral force resistance that a new house must meet today. That does not mean the house will collapse — but it does mean it was not engineered for the ground motion that the Phivolcs atlas now says is possible.

Renovations That Changed the Structural Load Path

Many homeowners in older subdivisions add a second floor, convert a garage into a room, or replace a lightweight roof with concrete. Each of these changes increases the building’s weight — and therefore the seismic force it must resist — without necessarily adding the shear walls, moment frames, or diaphragms needed to handle that force. A structural engineer can evaluate whether the existing lateral load system is adequate for the new configuration, but this step is almost never taken unless a problem is already visible.

The Difference Between Pre-Selling and Existing Home Risks

For someone buying a newly constructed home in Merville Park — if any new construction is happening — the developer should have followed the current NSCP and ideally conducted a geotechnical investigation. For someone buying an existing home, the risk profile is entirely different. The buyer is inheriting whatever structural decisions were made decades ago, plus whatever modifications were done by previous owners. A pre-purchase structural inspection by a licensed civil engineer is the only way to know what you are actually buying.

Financing and Insurance Complications

Banks and insurance companies are becoming more aware of seismic risk in Metro Manila. Some lenders now require a structural assessment for older homes before approving a mortgage, and earthquake insurance premiums can vary significantly based on location and construction type. A home in Merville Park that has not been structurally evaluated may face higher insurance costs or difficulty securing financing, particularly as more granular hazard data becomes publicly available through the Phivolcs atlas.

What You Can Actually Do: A Practical Guide for Merville Park Residents and Buyers

Commission a Geotechnical Investigation Before You Buy or Build

If you are considering purchasing a home in Merville Park, the single most valuable expense is a geotechnical investigation. A borehole drilled to at least 15–20 meters will reveal the soil profile, groundwater level, and liquefaction potential. The cost — typically PHP 30,000 to PHP 60,000 depending on depth and location — is small relative to the purchase price of a home and provides data that a structural engineer needs to evaluate the foundation. Without it, you are guessing.

Hire a Structural Engineer for a Seismic Vulnerability Assessment

For existing homes, a structural engineer can perform a rapid visual screening followed by a more detailed analysis if needed. The assessment will look at the lateral load path — how forces travel from the roof to the foundation — and identify weak points such as soft stories, irregular layouts, or inadequate connections between structural elements. The engineer can then recommend specific retrofits, which might include adding shear walls, installing steel bracing, or strengthening the foundation. This is not a cheap process, but it is far cheaper than rebuilding after a major earthquake.

• 1
  Engage a Licensed Geotechnical Engineer

  Request a borehole investigation to determine soil type, bearing capacity, and liquefaction potential. The engineer will produce a geotechnical report with recommendations for foundation design or retrofit.

• 2
  Commission a Structural Assessment

  A structural engineer reviews the existing building plans (if available) or performs field measurements to document the current structural system. The output is a vulnerability report with retrofit options.

• 3
  Implement Recommended Retrofits

  Depending on the findings, retrofits may include adding concrete shear walls, installing steel moment frames, or improving foundation connections. Work must be done by a licensed contractor and inspected by the engineer.

• 4
  Update Insurance and Financing Documents

  Once retrofits are complete, provide the structural report to your insurance provider and lender. A certified seismic upgrade may qualify you for lower premiums or better loan terms.

Understand the Limits of What Engineering Can Guarantee

No building can be made completely earthquake-proof. The goal of modern seismic design — and the philosophy behind Ayala Land’s approach in developments like Park Terraces and Parklinks — is to ensure life safety and, in higher-performance designs, to keep the building functional after a major event. For a single-family home in Merville Park, the realistic objective is to prevent collapse and allow occupants to evacuate safely. Retrofits that aim for “no damage” are possible but extremely expensive and rarely justified for existing residential structures.

What to Watch For in Policy and Data Updates

The Phivolcs Seismic Hazard Atlas is not a static document. It will be updated as new data becomes available and as seismic monitoring improves. Homeowners and buyers should check for updates every few years, particularly if a significant earthquake occurs nearby that provides new ground-motion records. Additionally, local government units in Pasig City may adopt stricter building code enforcement or require seismic assessments for older buildings during permit renewals or property transfers. Staying informed about these changes is part of responsible homeownership in a seismically active region.

Frequently Asked Questions

Living in Merville Park means living in one of Metro Manila’s more established and desirable subdivisions. The trees are mature, the lots are generous, and the community is well-established. But the ground beneath it does not care about any of that. The seismic hazard is what it is, and the only variable a homeowner controls is how seriously they take the engineering data now available. The Phivolcs atlas, the NSCP updates, and the engineering practices of developers like Ayala Land all point in the same direction: site-specific knowledge, not general assumptions, is what determines whether a house will protect its occupants when the ground starts moving. If this was useful, you might also want to read how earthquake risk affects property values in Dasmariñas Village.

Sources

Expert insight on earthquake engineering and home safety in Filinvest East Homes — A closer look at how engineering principles apply to another established Metro Manila subdivision, with practical advice for homeowners.

Phivolcs unveils seismic hazard atlas to enhance quake safety. Manila Bulletin, 2024.

How Ayala Land Designs Buildings for Earthquake Resilience. Ayala Land, 2024.

Earthquakes: Planning architecture, engineering and design to address hazards before they become disasters. The Manila Times, 2025.