there is a running thread for this general topic (graduate school). I think getting a rec, and explaining to that rec that you want them to write in some "damage control" about your lower than average gpa, could not hurt. provided you trust the recommender well enough to do an adequate job.

I am curious as to how close you are to your degree at Columbia College; depending, it may quicker to complete your degree and apply to a MArch rather than transferring to an undergraduate degree.

They may see your spring grades as they may not make a decision without them considering your current GPA.

I would obtain a letter of recommendation, but I would talk with UIC and see what they want. Go visit.

Hmm, I guess I did the same kinda thing, only in Wisconsin. I had a pretty dismal 2.3 GPA in computer science, but I was allowed to transfer to UW-Milwaukee as a generic Letters & Science major, since they only required a 2.0. The first two years I just took freshman & sophomore level arch classes (because anyone can, and it helped that I transferred and technically was considered a senior, so I could sign up for classes before the sophomores), and finished up whatever gen eds I didn't have.

Even though I was technically a L&S major I was allowed to take the sophomore level studios. After the first two studios I submitted my portfolio (along with every other sophomore, since UWM weeds out undesirables after the soph studios) and my GPA (which was 3.3 for those first two years). It helped that my first studio professor was also the chair of the selection committee and liked my work. After getting through that "gateway" my adviser just switched my major to Architecture.

I would contact UIC's undergrad adviser for Art & Design and see how the process of transferring there would work.

Is it your non-design grades bringing you down, or are your interior architecture grades bad?
Def. talk to UIC -- if you have strong design grades you MAY be able to apply for advanced standing and go straight into 2nd year arch. studio, playing catch-up with the rest of the class load. If you don't get advanced standing I'd be hard-pressed to see why it would be worth transferring at all, unless you just really need to save some dough, which is understandable if so. Supposedly Columbia College is $$$...
A good letter of rec is ALWAYS a help, however. Just be sure -- ESPECIALLY if you are asking for a damage control letter -- that you give your recommender at least 30 days of warning. In other words, go ahead and ask for the rec NOW -- even though it may take you a few days / weeks to get the answers you need from UIC. If you end up not needing the letter, so be it -- but that is not something you want to rush.