Go to an office or copy store and have good quality copies made of your art work, and put it in a nice looking black binder. Even if your art wasn’t done in an art class it still counts! Espeically since you like to design buildings. Include mostly the building art, but also include a few abstract pieces that are your favorites (it’s also good to get opinions on which pieces of your art are other peoples favorites). If you include both types of your art it shows how well rounded you are. Find out too if this is more of a design based school or a technically based school and prepare for your interview accordingly. Some schools focus more on the design and theory process of architecture while others focus on the detail, Auto CAD, and actual building processes involved in the architecture. Also include any Auto CAD work you may have done (This is a BIG plus now a days!), or any Photoshop or other computer generated work you may have been involved in.