Existence is related to Preserve. Preserve is the opposite of Ruin. Ruin is the opposite of Construct. 
House is related to Building. Building is related to Farm. Farm is related to Peasant. Peasant is related to Agriculture. 
Existence <--RelatedTo--> Preserve <--Antonym--> Ruin <--Antonym--> Construct 
House <--RelatedTo--> Building <--RelatedTo--> Farm <--RelatedTo--> Peasant <--RelatedTo--> Agriculture 