But analysts warn that the plan – dubbed gentengisasi , or mass roofing – could strain the environment, require costly structural upgrades and receive a lukewarm reception in regions outside Java.

“If we remember, our grandparents used thatch or palm fibre to make roofs or other natural materials, so the [air] in their houses was cool. Back then, [the houses in] my mother’s village in Minahasa used thatch as roofs. Now, it’s all zinc, zinc.”

According to Prabowo, revitalising the dying roof tile industry would “not be expensive”.

“The raw material for roof tiles is soil, and by mixing it with other waste materials, it can be light and strong. I received reports from our professors that coal waste, mixed with soil, would make a good roof tile material,” Prabowo said.