Translation:You are not going to be at your house until Friday.
Not at all. Let say your house was fumigated for bugs. The fumigators would tell you, "You can not be in your house until Friday. It needs time to air out." Or a real estate agent might say, "We need three days to record your deed. You can not be in your house until Friday."
Yes, and then you tell your friends that I won't or will not or am not going to be at my house until Friday. One of them is bound to wonder why but you may or may not tell them. So, one of them repeats it back to you to make sure they understood you. "You won't be at your house until Friday."....
Your sentence is about "going" to the house, this sentence is about "being" at the house. "vas a estar" - "vas" = you are going", "a" = to, "estar" - to be. "No vas a estar en tu casa" - You are not going to be at (in) your house.
In your example, you would use "ir" instead of "estar"; either "no vas a ir" (you are not going to go) or "no irás" ("you will not go").
Hope that makes sense....