First -- key into the relationship you had with your grandpa and understand that relationship and what he means to you.
The house and your grandfather's appearance in the dream really speak more of something that you may be holding on to without accepting that there is no more life in the house and your grandfather is only alive to you now in the inner circle of your heart.
So I feel that you know the core tie in your relationship with your grandpa. Let go of the old and accept the treasure in the memory you have of the house and the love you and your grandpa shared -- it is something you can carry with you like in a small bag or pouch.
Did you get to tell him goodbye before he died in real life? If not then that was your way of saying goodbye. where were you in real life when he died? Did he have a will? were you in it? need more info
And we are supposed to tell you what that means? It's about as personal as personal things get and arranged specifically for you and we are supposed to know what that means?
Looking deeply in your dream is pointless but the basic jist is that he came to you to tell you he loves you. is there something going on in your life thats stressing? you should ask yourslef why he came to you and maybe what you got from the house was the peace you needed to figure things out in life.