Many apartment buildings in Hanoi are more than 40 years old and pose a threat of collapse, but relocating their occupants to renovate them is not an easy task. 

Old condos in Thanh Cong Ward, Ba Dinh District. The city has 1,579 apartment buildings that are 40 years or older, and only 18 of them have been upgraded or rebuilt and work is going on at 14 others.

Of them, 179 are classified as "dangerous" or "severely damaged." Most were built between 1960 and 1994, though some before 1954, when Vietnam achieved independence from the French.

A condo building named G6A with three units on Nguyen Hong Street in Ba Dinh District. Built in 1987, it is classified as "dangerous."

Many families have modified their own units, more or less affecting the load-bearing capacity of their buildings.

A sign on a building to warn people about its degradation and the danger it poses.

The wall along the stairway of G6A has turned moldy and peeled off.

Fearful of the danger, several families have abandoned their houses and moved out.

A kilometer away, Ngoc Khanh apartments on Ngoc Khanh Street in Ba Dinh District, built in 1985, have also seriously deteriorated.

A part of the building has been classified as "dangerous" and occupants have been told to move out.

The ceiling is peeling off in places in Ngoc Khanh.

C8 Giang Vo condo was built in 1975-1980. The landings from floors 1 to 5 were reinforced with steel beams 10 years ago.

Some families continue to live in the building despite being aware of the danger. Most of them say they have lived there for 20-30 years and do not want to change, especially because of its location in the downtown Ba Dinh District.

If they move, they would be resettled in the Phap Van residential area 10 km from downtown, which is much less convenient, they say. In many cases, people also wonder how the city will compensate them.

But several families have already moved out, abandoning their apartments.