I would describe the durability of this plastic ramp to what you would expect from very large, plastic, children's toys: Outdoor Play House, Kitchen, Tool Center, Ride-On, etc. Think Step # or Little T*k**. There isn't a back side or an underside enclosure on this sturdy ramp. If there were at least a bottom board, it would create an easily moveable, storage space (just pick up and move). I have to move my ramp a couple times a week to keep my wobbly grand-baby from trying to figure out how to crawl up. I have tile flooring. HOWEVER, if your ramp will stay in one place all of the time, that won't be an issue and you could easily store items under the ramp. NEVER STORE dangerous items (medication, poisonous products, choking hazards, strangulation hazards, sharp objects, etc., items that have the potential of making a mess, or items you don't want ruined) as these items could be accessed by children or pets. Per the sticker on the white basket in the pic it measures 13.75 L x 11.38 W x 8.75 H. The white basket is pushed all the way in until its height stops it. Compensating for the basket's taper, in case a no-taper basket is used, I turned the basket upside down to calculate the extra room still available under the ramp for a larger basket (only if the basket's height isn't greater than 8.75".) There are 4" between the white basket and the internal side of the ramp's back, bottom bar. Turning the up-side-down basket 90 degrees, it takes up all of the ramp side to side. There would be no room for a lid. There are 6.75" between the white basket and the internal side of the ramp's back, bottom bar. Just to be sure of fit, these two measurements are slightly under what is actual. At the front of the ramp, there will be a small amount of underneath storage space available. That amount depends on the size used as the main basket. For being on a tile floor, my ramp STAYS IN PLACE pretty well. When there is too much movement, I use a damp cloth to wipe the floor under the ramp and the included anti-slip tabs on the bottom of the ramp to remove dust and debris. Unless you require a super light weight product, don't waste your money buying the washable, zip-off cover with furry / fuzzy steps. Those are likely constructed of cardboard. While cardboard can be sturdier than you might imagine, these types of steps could be ruined if they come into contact with liquid or absorb unpleasant odors.