I decided to go with a 2 grid by 2 grid because of spacing in my living room....theres not a lot of it until we move in december. After we get settled in our new home, I will be able to add the 3rd grids making each side 2 x 3 grids. But for now...this is enough space for Oscar and Lola to romp around in compared to what I temporarily had them in. After I put them in..they were so overjoyed and happy that they both ran around and popped all over the place! I won't have to cut the middles down either cause they were able to see each other just fine over the coroplast..they even sniffed each others noses and Oscar was "purring" all about. It was nice to see them so happy! My top didn't come out like I wanted though. I bought 2 closet shelf units and thought they would meet in the middle so I could cable tie them in the middle to make flip up lids..but for some reason..there was a space of about 7 inches so I had to add grids across the middle and tie them in to place. Any one know why? And I made the coroplast 29" x 29"...I hacksawed the connecters so that the coroplast would lay flush against the sides of the grids so there would be no space. My fingers and my thumbs hurt bad now from sawing, tying, connecting, cutting, scoring, folding, and taping!!!! Started at 10am and finished it all by 3pm...had to take diaper changing breaks, snack breaks and lunch break with my 20month old son. LOL. My back is killing me and so are my feet. Man..this was like doing manual labor!!! LOLOL