I've seen clothing that was crocheted using sewing patterns, and they are pretty neat! In fact, an old Crochet! magazine has a tutorial about this. If you're interested in which issue, let me know, and I'll hunt it down for you. I know you're interested in knitting, but the information in this article still might prove helpful.
A couple of things to think about when knitting to a sewing pattern--make sure you allow for enough (but not too much) ease because knitted fabric behaves differently than regular fabric. Also, your knitting seams probably won't need to be as wide as those for a regular sewn garment. Additionally, remember that certain stitch patterns tend to stretch in different directions. So inserting the right knitting stitch pattern in the right place is essential if you don't want, say, a droopy skirt or a stretched out waistband.
Sweater Design in Plain English by Maggie Righetti has some very helpful information about the ways and means of knitted fabric OR you could just do up a library of swatches and find out for yourself how they behave!
And lastly, Joan McGowan-Michael (whiteliesdesigns.com) has some knitted/sewn garments. Well, she at least has one that I know of in Creative Knitting magazine July 2012 issue. Oh, wait, the article says she has more such garments in a book called Knitting Lingerie Style.