Throughout the Kingdom of Bhutan, you can see rocks on top of simple roofs to help prevent them from (presumably) flying away. I'm not sure if this means that rocks are cheaper than nails here or what, but seems like a simple and hopefully effective solution.
While Bhutan is very forward-thinking in terms of environmental conservation and tries to be a green country, it's not without its challenges. Much of the country is pristine beauty, but when you get into the urban areas, waste does become an issue. Even this building has waste littered about its grounds.
Building in Lobesa-Metsina with a splash of color applied.