The house in "The Deserted House" is a metaphor for a dead body or dead person.
The poem opens with "life and thought have gone away" speaking of a person who has died and no longer has life or thoughts. It continues in Lines 1-3 describing the emptiness of the house, showing the stillness and emptiness of death.
In Line 4 "The house was builded of the earth, And shall fall again to ground." refers to a body being buried, similar to the common funeral phrase "from dust to dust"
Line 5 refers to the person in Heaven- "in a city glorious-- A great and distant city--have bought A mansion incorruptible." Incorruptible in this line means everlasting or unable to decay, showing that the person, (the "mansion") will stay there forever.
The poem ends with "Would they could have stayed with us!" in reference to the person who has died-wishing they had not "moved" to heaven and instead could have stayed alive.
