Thread: modular shelves for garage and stability

The storage situation in my (single car) garage has gotten so out of hand I can no longer get to the workbench or exercise equipment to use it, so I'm looking at setting up some storage that utilises the vertical space. The plan is to have shelves along one wall and work bench and exercise equipment along the other wall (both ends have roller doors so there is only 2 walls).

The challenge is that I'm renting which means I don't know if the garage space will have the same dimensions next time I move and I won't be able to bolt shelves to a wall to prevent them from falling over. In order to get around the first problem I want to build modular shelving - basically big wooden boxes stacked on each other, like this: Way Basics - Tool-Free Modular Storage Cubes Plus - modern - bookcases cabinets and computer armoires - - by 2Modern I figure that when I move I will still be able to use them but possibly stacked in a different configuration.

My main concern is whether such a modular system stacked most of the way to the ceiling would be dangerous in terms of stability if I'm unable to bolt them to the wall. My own thoughts on this are:

1. If heaviest items are stored in the bottom cubes and lightest at the top it might help stability; or
2. If I made bigger cubes for the bottom and made slightly smaller cubes for each higher level I could stack them like stairs and this might create more stability as there would essentially be a bigger base.

So, I'm after thoughts on what measures would be necessary to ensure this design is safe from toppling over.

I'm also after thoughts on what material to use - I'm trying to keep it affordable so would consider using plywood, MDF or chipboard. I'd appreciate any advice on which might be the best way to go in that regard. Thanks.