Tuesday's enforcement of a law allowing municipal governments to order the demolition of hazardous vacant houses has sparked concern among local groups and activists who say the legislation is not enough to address the growing problem.

While communities have been working to demolish empty houses through ordinances, citizens' groups argue the latest law will only cover a small number of empty houses nationwide. But many groups, claiming the number of derelict homes in reality is much larger amid Japan's declining population, seek to preserve the value of the dwellings as regional assets.

"Vacant houses are not a burden, but an asset of high cultural and historic value," said Masako Toyota, 40, head of the Onomichi Akiya Saisei Project, a nonprofit organization that renovates vacant houses to promote local culture and tourism.