We have a spacious 3 car garage that also has a pull down ladder to some storage space in the attic above it too. Don't plan on moving from this house for a long time but if we ever do unless there is a decent shed on the property I don't know how I can live without that 3rd stall which is essentially my shed. I will say that my garage is usually a big unorganized but I do clean out and re-organize it twice a year when I shuffle things around for summer and winter. One of the previous owners did a great job building some really sturdy wood shelving and work bench along the back wall while still allowing enough space to get 2 cars parked in without being cramped.
So what I have in my garage is I keep both trash and recycle carts inside in front of 1 car while there is a single shelf above that. Have our stand up deep freezer in front of that stall as well. the next stall there is a tall set of wooden shelves I store tools and supplies on then to the left of that is a work bench with an overhead shelving unit. the top shelf extends all the way across to the 3rd stall and along part of the side wall of the 3rd stall when it makes an L for about 5 or 6 feet too. In the 3rd stall have my lawn mower, snow blower, garden tiller, bunch of kids outdoor stuff, garden tools and supplies, grill, and some misc items then in the fall I reshuffle it so I can store my patio furniture inside. The 3rd stall I get pretty organized then it just becomes a big mess between organization efforts as I take things in and out. In the garage attic I store all my Christmas decorations and lights and anything I rarely ever use. If I didn't have that 3rd stall I would have built a shed by now because we wouldn't be able to park the cars inside if we didn't. My last house was just a 1 car garage but had a good sized shed in the back yard but have also accumulated more stuff since then too.
You're not afraid that the mysterious beast living up there is going to savagely rip your head off the second you peak above the access portal?


