I have just built a new house on a lake and have an attached garage bigger than the first floor of the home (~1500sqft). What else would someone do with so many water toys (and cars)....gotta keep them up, right? The walls are 12' with open ceiling structure that reached about 24'. I have room for a loft and a machine shop upstairs. The main area of the "toy" garage (not including a standard 30' wide, 22' deep double/single door standard garage arrangement) is about 20' x 40'. The loft will be partially over this area and over the other standard garage. Knowing I want to put a machine shop, engines and transmission storage in the loft, any ideas on how to design the floor structure? I am thinking I'll do a 4"x10" steel I-beam on one side and put a ledger to the home on the other side. Do I need additional support to ensure the sheer load on the home wall does not get too high? Suggestions?