Subtract the interior curves inside of a rectangle

[Cem_Cetin]

hello!
This may be too easy to do but I couldn’t do it. As you can see in the image I want only the interior curves and remove the boundary of the house. I tried trim with region components etc. but couldn’t do it.
Anyone can help me with this?
Thank you!

[Joseph_Oster]

BBox assumes your house is rectangular… If it’s not, Boundary works instead:

[Cem_Cetin]

Thank you!