People have reported similar stories from Turkey and Greece, for what it's worth. No one seems to agree whether it's about tax stuff or leaving the option to extend dwellings by another floor.

In Yemen the practice is to have the top floor of a dwelling be the mufraj (room with views where men chew qat) which is what makes me skeptical about the tax idea there. The buildings certainly don't look unfinished from rooftop level.

The thing that makes me most skeptical, though, is just that it's such a wonderful, repeatable story.