Answer:
This is an example of metaphor.
Explanation:
A metaphor is a type of trope or rhetorical figure in which the meaning of one concept is transferred to another, establishing a relationship of similarity or analogy between both terms.
Metaphors are images or words whose association is suggested or summoned in a text. This association produces impressive relationships that resize the literal meaning of words or images.
This can sometimes be mistaken for a simile. But for this example to be a simile it should be written in the following way:
Heaven is like my roof and the whole world is like my house
