Low-rise housing developers should invest more in structural reinforcement to improve resilience against potential future tremors, which are likely following the earthquake in Myanmar in March, according to the Thai Structural Engineers Association.

An artistic impression of townhouses at the Patio project on Kanchanaphisek Road in Bangkok. All of Pruksa Real Estate's low-rise houses are constructed using the precast concrete system. Kanana Katharangsiporn

Prof Amorn Pimanmas, president of the association, said the recent earthquake prompted the construction industry to adapt by improving building safety standards to minimise potential damage, especially in high-risk areas such as Greater Bangkok and the northern provinces.

"Enhancing building safety comes at a cost," he said. "But it's a worthwhile investment as it provides both protection and peace of mind for homebuyers who are increasingly concerned about future earthquakes from the Sagaing Fault in Myanmar."

Prof Amorn said the fault caused the tremors felt in Greater Bangkok in March and may strike again as it is one of the most active and powerful fault lines in the region, with the potential to trigger large-scale earthquakes.

The Sagaing Fault is geologically linked to major faults in Thailand, such as the Si Sawat and Three Pagodas faults, both of which could be activated and result in quakes of up to magnitude 7, within close proximity to Bangkok.

The capital is situated on a soft soil basin that amplifies seismic waves, making high-rise buildings especially vulnerable.

While Thailand had a ministerial regulation on earthquake-resistant design in place since 2007, along with engineering standards for seismic loading, the recent event has heightened public awareness of earthquake risks.

"Although the cracks that appeared on the walls of some low-rise houses during the recent tremors were not structural and did not pose a threat to life, homeowners still faced the burden of repair," he said.

Structural reinforcement for low-rise homes in earthquake-prone areas can significantly reduce potential damage. Measures include wrapping columns with steel ties and reinforcing walls with concrete and rebar, said Prof Amorn.

"Earthquakes along the Sagaing Fault are inevitable," he said. "But serious damage can be prevented or at least mitigated by choosing stronger structural systems."

After the Myanmar earthquake on March 28, the association and 660 experts surveyed high-rise buildings.

Only 10 showed structural damage, while the remainder had no structural issues, though cracks on non-structural walls were commonly observed.

"We found no cracks on precast walls," he said. "We have full confidence in their strength, as they are factory-produced. However, joints that connect all precast components must be carefully designed and constructed to ensure they remain intact during an earthquake."

He recommended that homebuyers consider several factors when choosing a low-rise house. These include checking which engineer designed the structure, evaluating the quality of materials such as steel and concrete, and ensuring the design complies with ministerial earthquake-resistance standards.

"Buyers should also check whether the unit has undergone seismic testing," he said. "Although this type of testing involves extra investment from developers as they must send their products to a lab for evaluation, it helps build confidence among homebuyers."

Pichet Wichitchamnan, executive vice-president at Pruksa Real Estate, a subsidiary of SET-listed Pruksa Holding, said the recent earthquake has raised concerns not only among condo buyers but also those purchasing low-rise houses.

"Peace of mind and a sense of safety are fundamental when buying a home," he said. "All of our low-rise houses across more than 100 projects use a precast concrete system, which offers strong earthquake resistance. The walls bear loads well and show no cracks."

However, he said that some buyers in the past preferred low-rise homes built using conventional methods, as they allowed more flexibility for modifications, something not possible with precast walls.

To meet this demand in a highly competitive and currently sluggish market, Pruksa will now offer an option for customers to use conventional walls in areas where they want flexibility for future changes.

"The most commonly modified areas are the kitchen at the back of the unit and the second-floor bedrooms, which some buyers want to combine or divide," Mr Pichet said.

"Now, during the design phase, customers can inform us where they want flexibility, and we'll build non-load-bearing walls in those areas."