How to make holes in a box?

#1 Use the CSG subtract function , while using another box like a cookie cutter then you'll see there are hole...well make sure you hollow the box first, does this help?

#2 Well, I did what you told but it didnt do any hole. Do you have to hollow the box you make the hole in or the cutter box that makes the hole? I tried both but maybe there is a way to hollow boxes that i dont know.

#3 1. Make box.
2. Click the Modify tab on the left panel.
3. Click the Hollow icon.
4. Click OK.
5. Click the Create tab on the left panel.
6. Make smaller box. This is the "window" block.
7. Move smaller box where you want a "window". Make sure it fits in the area you want to carve.
8. Click the Modify tab on the left panel.
9. Click the CSG subtraction icon.
10. Delete the "window" block.

#4 I got it now, but when I did the hole, other lines on the big box appeared (???). But Thanks. By the way, do you know how to use the zoom function? Because sometimes, it feels stiff. Thansk again.

#5 Of course they do. You are creating geometry by carving.

#6 Can you tell me how to create windows in constructor? (If possible, breakable (which I supposed it needs an animation))

#7 Create your windows as DTS objects in another application (such as 3D Studio Max or Blender) since they can be both transparent and breakable.

#8 Is blender 2D or 3D? I've downloaded it on their website, but i cant figure their 3-dimensional plan out, which is very unlike 3dsmax.

#9 It is both (like Max). You can either create 3D models or render out 2D images of them.