Passive voice - The house is remodeled to help it sell by the homeowners.
Since the house is an object, the passive voice always starts with an object. To find if its a object just ask what the homeowners remodeled? Then you will get the answer as the house and to find the subject just ask who remolded the house? Then you will get the answer as homeowners. I hope you got it because I like people who ask questions to me.