The only thing plastic is the slide and the actual swings. The rest is wood. I didn't design it to be modular. Just got bored, wanted to build something for the kids, went down to home depot and...voila! If you're handy with a hammer you shouldn't have any problems taking it down far enough to transport.
Besides...do you know how much a "modular" one costs? I'm GIVING this one away. Do you really want to nitpick?