Inside the plugin is a bedroom lit with warm yellow light and a bathroom with sleek faucets, showerhead and toilet. (Photo/Ecns.cn)

When Dashilar was a thriving commercial street during the Qing Dynasty (1644-1911), each courtyard house was occupied by a single family. As Beijing's population soared, Dashilar became overcrowded, with up to eight families packed into one house. The houses began falling into disrepair decades ago, as residents began relocating to newer buildings.

Yet the government has been reluctant to resort to expensive mass overhauls, and some residents are worried that it may rob the neighborhood of its soul. Moreover, as the majority of these houses have several families under one roof, renovation of one room often affects other spaces.

"People just leave the houses to rot," Shen said.

To make Dashilar look better, the government has covered some exterior walls with grey tiles. But cheap tiles easily peel off, and the interior of the courtyard houses remain in poor condition.

"That's why we need a more affordable and flexible plan," said Jia Rong, executive director of Dashilar projects. "The plugin is an easy and fast way to make use of scattered spaces, and it's an independent box, so impacts on neighbors are minimized."

Although not everyone in the neighborhood notices the change in courtyard 72, Shen said they've been getting good feedback from the government and people who come to visit.

"They've heard that it's convenient, fast and affordable, and they're considering it instead of doing renovations," Shen said.

The idea isn't without shortcomings, though.

Wang Xiuren, 61, a descendent of Ji'antang whose family used to own courtyard 72, expressed her doubts about the septic tank.

"I'm not sure about the hole beneath the yard," she said. "Will it pose potential risks to the house?"

In an email interview Shen explained that the underground water pit could help store rainwater from the yard. "The older the courtyard, the lower it is in relation to the street, so rainwater has nowhere to go. The pumps inside will help drain the pit once water reaches a certain level."

Dong, who occasionally takes walks in the yard and answers questions from visitors, said she likes the idea, but would be happier if there's a subsidized renovation.

"I'm afraid the box isn't strong enough. You can see that my roof is leaking and the pillars are falling. I hope these can be fixed before I consider modern living," Dong said.

"The plugin is a temporary solution," said Jia. "But we think it's an excellent idea overall at this moment and will spread to other scattered spaces. Meanwhile, we'll keep soliciting good ideas."

According to Shen, the team will finish a dozen more plugins by October. The spaces may be used as incubators or offices for NGOs and culture or art related groups.

"We hope our design relates to people's daily lives and fits the style and traditions of the area," Shen said.

Wang, who was born and raised in Dashilar, said she's glad to see these young people from home and abroad contributing their brain power to the neighborhood.

"Their project may not be perfect, but I really appreciate their passion and experience," she said. "Many of the neighbors have moved to newer apartments, but I want to stay and see Dashilar revive."