built-up area

洲本で起きた凄惨な事件は責任能力が焦点になりそうです。

ここのbuilt-up areaは文脈から明らかですが、一応、starlightさんにたずねてみます。（Kawada）

Man arrested after fatal stabbing of 5 in Hyogo

The homes where the attacks occurred are located in a mountain region dotted with rice paddies and fields, about 3.5 kilometers north of the built-up area where the Sumoto city hall is situated. The two homes where the attacks occurred lie within a radius of about 50 meters from Hirano's home.

http://mainichi.jp/english/english/newsselect/news/20150309p2a00m0na017000c.html