Rooftops make great gardens, especially in dense urban environments where every available space has been utilized for living and for commercial purposes. In many cities around North America, Asia and in Europe too, where outdoor space is scarce, architects and builders are turning rooftops into playgrounds with swimming pools and vegetable gardens. But in Jakarta, Indonesia, one developer has converted the rooftop of a shopping mall into an entire suburb of sorts with houses, paved streets, a tennis court and lush greenery.

Cosmo Park on top of Thamrin City Mall. Photo credit: Shahrir Bahar/instagram

Cosmo Park is perched ten stories up on top of the Thamrin City Mall in Central Jakarta, but looks and feels like a real suburb on the ground. Inside the 3-acre rooftop, there are 78 two-story houses with neatly laid asphalt roads where kids cycle and elders jog or walk their dogs. Residents can drive their cars all the way up to the roof via a ramp. A tall metal fence runs around the perimeter to make sure no one falls or drives off.

Residents of Cosmo Park feel the community is safer than a regular suburb, being located on top of a building, yet is not as isolating as living in an apartment.

“It is so good. There is so much open space, my son can ride his bike around. It’s so central, it’s really safe, and there is a lovely neighbourhood feel,” one resident named Fazila Kapasi told The Guardian. Kapasi has another reason for living in Cosmo Park. She and her husband moved there six years ago to escape Jakarta’s frequent floods.

“It’s a lovely oasis,” she said. “I cannot recommend it enough.”

Indri Lestari, another resident of Cosmo Park shares similar sentiments. “It’s high here, for sure. But lots of places are and here we have more space and privacy, and it’s better for my family. My son can play outside, just out the door.”

Photo credit: Muhammad Fadli/The Guardian

Fazila Kapasi and her son in Cosmo Park. Photo credit: Muhammad Fadli/The Guardian

Street-level view of Cosmo Park. Photo credit: Agen properti

Related: What Rooftops Tell About Hong Kong’s Residents

Cosmo Park is not the only village in the sky in Jakarta. There is another one, a luxury housing complex called The Villas, on top of the Mall of Indonesia, in North Jakarta.

A row of three-story houses visible on the roof of Mall of Indonesia. Photo credit: Creativa Images / Shutterstock.com

Street-level view of the same houses. These houses are sold at prices ranging from 3 to 5 billion Indonesian Rupiah, equivalent to USD 200,000 to USD 350,000. Photo credit: Vitorio Mantalean

With a population of over 10 million and three times that within the greater Jakarta area, the city may soon need to build more neighborhoods on top of existing buildings. Life on the ground has become unbearable for many due to chronic flooding that occurs every rainy season. This is exacerbated by the fact that Jakarta is sinking as more and more groundwater from underground aquifer is pumped out for drinking, washing and construction purposes. On top of that, the sea level in Jakarta Bay is rising every year.

Jakarta is among the world’s densest cities, on par with Tokyo, with about 14,000 residents per square kilometer. But Tokyo and other megacities in Asia are growing vertically. In contrast, Jakarta’s density is sprawling horizontally with low-rise single-family houses. Such development leads to shortage of land leaving little space for affordable housing and parks. The city is depressingly low in green spaces—less than 10 percent of the city’s land area is allocated to open parks and gardens.

Cosmo Park on top of Thamrin City Mall. Photo credit: www.medcom.id

Wendy Haryanto, Executive director of Jakarta Property Institute, believes that the only way to make Jakarta livable is to build upwards. Government-owned enterprises, she points out, own vast amount of land in strategic areas but these land has low floor area utilization, because they are often used for a single and limited purpose, such as to serve a market or a bus terminal. Wendy proposes that they take these under-used buildings and build multistory low-income apartments on top of them, the same way the Thamrin City Mall and the Mall of Indonesia have done.

“This could be a win-win solution,” she writes. “Public enterprises earn extra income from unused air rights for developers to build low-income apartments that they are obligated to construct anyway; markets get more business; low-income households live in the city.”

Wendy is hopeful: “Once some residents of low-rise housing have moved to nearby vertical flats in TODs, Jakarta can carve out land for green areas. This will help Jakarta fulfill its obligation to allocate 30 percent of its land for greenery.”

Cosmo Park on top of Thamrin City Mall. Photo credit: www.medcom.id

Cosmo Park on top of Thamrin City Mall. Photo credit: www.medcom.id

Cosmo Park on top of Thamrin City Mall. Photo credit: www.medcom.id