Nestworld

noun
A type of artificial habitat composed of multiple twisting tubes, complexly intertwined.
Source
Matter

Shellworld

noun
An artificial planet comprising a solid core surrounded by a concentric succession of spherical shells.
Source
Matter

Conapt

noun
A private apartment in a shared building.
Origin
Abbreviation of ‘condominium apartment’.
Source
Do Androids Dream of Electric Sheep?

Ringworld

noun
A ring-shaped artificial habitat encircling a star.
Source
Ringworld