Ah, the fun parts of topology based modeling
Triangles are not nessacarily bad, they just don’t calculate correctly.
There are certain places, depending on how many triangles and where they are places, that it doesn’t really affect Sub-D too much…
There are structures(they look almost like a binary tree, if you know what that is) that take a large number of quads to a smaller number, you can probably figure out the details.
If you get their size and placement right, you can have the needed triangles without messing up your mesh at Sub-D levels.
Here is a fun way to figure things out:
Take a regular plane, extrude it a couple times so you have a column that is broken up into sections.
remove the faces/edges and then subdivide one end, so there are like 2 vertex’s on one end, and 8-12 on the other.
Now, if you turn on sub-d level 1, you will have a hollow outline of your box.
If you create faces or edges, it will fill them in, along with any underlying topology.
Play around with that simple plane until you figure out how to go from highpoly to low poly and keep the edgeloops and topology looking good.
It’s too hard to explain the structures without a tutorial, but play around and you’ll find methods that work for you.