The specialist states that the 2022 Census data allows us to understand housing exposure patterns, but not to determine how Dominican homes will respond to an extreme event
SANTO DOMINGO.- Although more than 82% of occupied homes in the Dominican Republic have block or concrete walls, this does not necessarily mean that the country is prepared for a major earthquake.
This was explained by engineer Ashley Morales-Cartagena, vice president of the United States Earthquake Engineering Research Institute (EERI), who warned that the 2022 Census should not be interpreted as a diagnosis of structural resilience.
“The first thing we need to establish clearly is that the 2022 Census does not measure seismic resilience or structural vulnerability,” the specialist stated in an interview with El Inmobiliario.
As he explained, census data does allow for the identification of patterns regarding predominant materials, population density, and territorial exposure, but not how buildings will respond to an extreme seismic or climatic event.
The material does not guarantee safety
Morales-Cartagena indicated that there is often a perception that a house built in concrete is automatically safe, when in reality the structural behavior depends on multiple factors.
“The material alone does not determine how a house will respond to an earthquake,” he said.
The specialist explained that aspects such as regulatory compliance, construction quality, technical supervision, and structural design are key to assessing the actual level of vulnerability.
Added to this is a common reality in the country: homes that have grown progressively with annexes, new levels or changes of use carried out without adequate technical supervision .
“That can modify the expected behavior of the structure under seismic loads,” he warned.
A vulnerability that changes depending on the threat
The engineer argued that the country faces a “multi-threat” reality, where the same constructive characteristic can represent advantages in the face of one risk and weaknesses in the face of another.
As an example, he cited the 2022 Census data which states that 47.5% of Dominican homes have zinc roofs, a percentage that reaches 72% in rural areas.
From a seismic perspective, he explained, a lightweight roof can partially reduce the structure's load. However, in the face of hurricanes and extreme winds, these roofs can become one of the most vulnerable elements, especially when they lack adequate anchoring systems.
“It’s not just about whether a house can withstand hurricane winds, but also what happens when storm drainage fails and an entire community ends up flooded,” he said.
Risk is not the same as threat
Morales-Cartagena stressed the importance of differentiating concepts that are often confused in public discourse: threat, vulnerability, and risk.
He explained that the threat is related to the probability of a natural phenomenon occurring, while vulnerability depends on the characteristics of the buildings and how prepared they are to respond to that event.
In the Dominican Republic, he said, there are areas with significant seismic risk associated with active faults, especially in the north of the country and parts of the southern region. However, the risk increases when this threat coincides with informal construction, disorganized urban growth, and a lack of technical oversight.
“The 2022 Census allows us to identify some relevant territorial patterns, but to talk about structural vulnerability, specialized assessments are required,” he pointed out.
The country still does not have a comprehensive diagnosis
The specialist explained that there is currently relevant technical information on seismic hazards, floods and landslides in the Dominican Republic, although it remains fragmented and with partial coverage.
He indicated that institutions such as the National Geological Service have developed seismic microzonation studies in cities such as Santo Domingo and Santiago, while the National Office of Seismic Evaluation and Vulnerability of Infrastructure and Buildings (ONESVIE) has carried out evaluations in schools, hospitals and essential buildings.
However, he believes that the country still needs more comprehensive models that combine census information, technical studies, satellite images and field surveys to achieve more complete risk diagnoses.
“The Census does not replace specialized technical assessments, but it does provide a fundamental basis for understanding exposure and supporting more comprehensive risk studies,” he said.
Reinforce, rebuild, or relocate?
Regarding possible solutions for vulnerable housing, Morales-Cartagena stated that there is no single answer and that each case requires technical evaluation and economic feasibility analysis.
He explained that some buildings can benefit from targeted reinforcements, while others require reconstruction due to structural deterioration or modifications accumulated over time.
He also pointed out that there are situations where the main problem is not the house itself, but the place where it was built.
“There are flood-prone areas, riverbanks, or unstable hillsides where relocation may be the only sustainable long-term solution,” he said.
According to the specialist, the country's main challenge is not only to build more housing, but to better understand existing risks and prepare for increasingly complex climate and seismic scenarios.
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