What is the meaning of Built-up?

Made of sections or layers, one on top of the other.

Having increased in size, quantity, or intensity over time; accumulated.

Constructed or enhanced.

Having buildings, especially having residences and high population density.

(of an area of land) Having street lights and therefore subject to a 30 mph speed limit.

(of an area of land) Having specific traffic signaling and therefore usually subject to a maximum 50 km/h speed limit.

Source: wiktionary.org