A visitor photographs a friend against colorful drapes at the block. The drapes draw on the site's textile heritage. [Photo/China Daily]

Three singers perform daily, according to Zhao. The restaurant usually stays open until about 2 am, although some customers remain until 4 am. Most of the evening crowd is young, he said.

At Yichi Garden cafe, Wan has seen repeat and first-time customers drawn by the building's Soviet-era atmosphere. Her team has adapted the space to accommodate different usages.

A room that attracted visitors wanting to take photographs proved disruptive for diners, so the team created a designated photo area downstairs, she said.

Wan herself has found the quieter corners useful.

"Sometimes, I retreat to a private room in the former experts' building, just to enjoy the calm atmosphere, so I can better concentrate my mind on the paperwork," she said.

Contact the writers at yangfeiyue@chinadaily.com.cn