Korea's government said it will only grant reconstruction permits to old apartment units that are deemed structurally unsafe, the strongest measure yet to tame runaway home prices.

Under the measure set to take effect as early as March, the government will raise the threshold of structural safety to 50 percent from the current 20 percent in assessing the overall safety of apartment units, according to the Ministry of Land, Infrastructure and Transport on Tuesday.

The measure means only apartment units that are structurally unsafe in will be torn down and rebuilt even if the apartment units are 30 years old, a minimum requirement for reconstruction.

The latest move -- the toughest action in about a decade -- represents Korea's firm determination to rein in home prices by using all available policy options.

The government has taken a set of measures, including tightened rules on home mortgages for multiple home owners, to calm housing prices in Seoul, which have risen too sharply in recent years.

The total market value of apartments in Seoul increased nearly 100 trillion won ($92.9 billion) last year to more than 860 trillion won, according to R114.com, a leading real estate website.

Prices for apartments in Gangnam, the most expensive district in Seoul, rose 13 percent to a total market value of 139.59 trillion won, according to data provided by R114.com. Overall prices in the entire southern part of Seoul increased 10.3 percent in 2017.

The price hike came as people borrowed money to buy apartment units on the expectation that housing prices would rise further.

The trend pushed Korea's household debt to more than 1,400 trillion won last year, which in turn has prompted the government to tighten mortgage rules for owners of multiple homes to keep mounting household from harming the economy going forward.

In 2009, the government lowered the threshold of structural safety to 40 percent from 50 percent in assessing safety of apartment units before lowering it further to 20 percent in 2015.

The ministry also said it is considering raising the minimum period for reconstruction of apartment units from the current 30 years, though it did not elaborate.

The measures could deal a blow to reconstruction projects of old apartment units in Seoul, where an estimated 103,822 households are subject to the tightened safety rules.

"Reconstruction projects of old apartment units will face difficulties for a considerable period of time," said Huh Yoon-kyung, senior researcher at the Construction Economy Research Institute of Korea.

Huh said the government is trying to use regulations on reconstruction as a tool to tame home prices rather than improve people's quality of life and noted that a previous government eased regulations because of such problems as floor noise and water plumbing issues.

Shim Gyo-eon, professor of real estate at Konkuk University, warned moves by the government to tighten regulations could result in a hike in home prices in Seoul due to an imbalance of supply and demand and said it could take time for reconstruction projects to be completed.(Yonhap)