Most modern outdoor projection equipment is, of course, digital. This would be a rather pricey rental item, try A/V rental firms.
You might be able to get by with an auditorium projector: if you only need it for a short time, and can put an educational/arty-farty slant to your usage, you may be able to borrow a few from a local university. Also try A/V firms, a big one might have some available for not that much money. These things normally take 3x4" (whatever the standard size) glass mounted slides. Using these with color transparency materials may be problematic as the light intensity in these things is fierce. Color ink-jet on mylar film might work.
Your second problem is 'the side of a concrete building'. You will need an outdoor projection screen, trying to project on concrete isn't going to work very well. Outdoor screens can be rented. You can make one from Tyvek and screen paint, or you can paint the side of the building with either screen paint or the best white titanium paint you can find.