Naturally, Japan presents the most examples in this article.

Naturally, Japan presents the most examples in this article. Other crowded places do probably not care too much about nicely designed space fillers, they just fill.

http://weburbanist.com/2014/04/21/no-lot-too-challenging-13-ingenious-odd-shaped-houses/
http://weburbanist.com/2014/04/21/no-lot-too-challenging-13-ingenious-odd-shaped-houses