Okay, so here is my problem. I've been trying to write a proper, novel-size story for the better part of a month now. The story is coming along well, I like the characters, and inspiration is coming at a steady rate.

That's not my problem. My problem is for the life of me, I can't make a chapter last any longer than 5-7 pages. Even stretching it out to the absolute limit, that's as far as I can take it in one chapter.

So I'm just wondering...does anyone have any tips or ideas on making a piece of writing longer, without it becoming more padding than prose?

I don't think you should worry about how many pages an chapter has.

After all, I've seen good novels where the first chapters only had like 4 pages and then as I read on the chapters started having more pages... even soon having up to 30 pages in an chapter!

I think it's mainly because the chapter are more focused on "scenes" or an string of scenes that related to each other focusing on an single theme...that in turn allows the author to expand that chapter.

and when the characters move on to the next "theme" or "chapter" in thier lives, that's when the next chapter starts.

I hope that makes sense.

Why are 5-7 pages few? It's is never quantity, it's quality. When I began writing The Art of Veiling I had a 6 page average for every chapter. The book (its final version that's been published) has 617 pages or so. It's quite hefty. So don't worry about how many pages you write- worry about how well they are written.

Get crackin'!

You could either work with your "disability" or against it... either is a workable strategy, and could force you to come up with some interesting solutions. When Kevin Smith didn't know how to sting together his vignettes of conversations for Clerks, he came up with the idea of prefacing each scene with a word in bold print on the screen. This technique is constantly used now.
You could also just match scenes that are linked narratively or thematically into one chapter. Are you dealing with only one main character? That would make it pretty tough.