Hi @Rahaf03,
Here are some things you can do improve the setup. I added the changes to the attached file.
You do not need the modifier subset. Instead you can add the modifier directly to the shade objects.
For the tree geometry I suggest that you convert it to a mesh. This will significantly reduce the number of polygons in your case. You can read more about the ShadeMesh object here.
The first two are mainly optimizations. The next one is required.
The aperture was added to the model several times. Below is the correct way to add the aperture as a subface. Basically, because the aperture is added to the room, you do not need to add it to the HB Model component as well.
