"Υπάρχει σκόνη στο σπίτι."

[bonbayel]

In other words, the house is dusty.

[alainPierrot]

at home ?

[katerinasiap]

This is partially wrong. If you say "the dust is at home" you mean that the dust has returned at its house or feels at home etc. The meaning of the sentence above is that the house is dusted and needs to be cleaned.