Wait. When did this morph into an argument of the existence of God? I thought we were talking about God being some sort of preferred relativistic reference frame.
> Besides that you can obviously build a house and enter through the front door after you finished it.
You did not enter the material house - you entered the empty space that was already there, which the material of the house surrounds. If you want to use the analogy you must actually change your physical body to be made of wood and nails.
> Wait. When did this morph into an argument of the existence of God?
You sort of brought it up yourself when you said "God created the universe." like it's a fact, didn't you? Maybe you could explain what that's supposed to mean here?
Discussing God as a reference frame seems to naturally evoke the question if he exists. And I am definitely more comfortable discussing whether God exists or not than if he may be a (preferred) (inertial) reference frame; probably one of the strangest things I have ever thought about.
Yes, the analogy with building a house is not really strong but on the other hand the whole question if God - if he exists - exists inside or outside the universe (read spacetime) is difficult to say the least. What is outside of space? What is outside of time? Out of what is God made? And how does this affect his possibility to interact with the universe? Is he even able to interact?
Now that I got your point with being something and building the same thing, self-organizing systems come to mind - that's probably as close as you can get to being something and building the same thing. This does not address where the matter for the system come from so it is more self-shaping than self-building but ad hoc that's the best I can think of.
> Besides that you can obviously build a house and enter through the front door after you finished it.
You did not enter the material house - you entered the empty space that was already there, which the material of the house surrounds. If you want to use the analogy you must actually change your physical body to be made of wood and nails.