Kathmandu, April 19 -- For a year or two after the 25 April 2015 earthquake, the residents of Kathmandu were too terrified to return to their high-rise apartments. None of them collapsed in the 7.8 disaster, but many sustained serious structural damage.

Fast forward nine years, and they have all but forgotten that frightful day. Kathmandu is back to building substandard structures, even as land prices drive developers to build taller.

With no more space to spread horizontally, Kathmandu is going vertical. But structural engineers say most of the high rises do not take into account seismicity, soil condition, construction methods, quality of raw materials, fire hazard, and search and rescue in collapsed concrete structures.

"Much of o...