What should it be?

I would make a 4x4 because it's equal on all sides, so it's more running room.

I would make a 4x5 then. With an upper level 2x5. You can put a "cozy room" in like Dagwell. I would leave it on the floor personally.

You could put in two, and make hidey houses out of them somehow. Maybe drap a towel over each one, like a tent.

Your welcome

I have a 4X5, The only bad thing is you will have to use two peices of coro. I think it woould be easiest just to make two 2X5's and connect them together.

Yeah thats how you wouold have too do it, thats the only disadvantages. I think with a 3X5 you can still only have to use one peice of coro. If i did it again thats what I would make it, but my mom says it has to stay this way for a while.

Its great that you have the room to make such a nice house. Please definately make another level. I have a 3 level cage and my piggies adore each and every level. I originally had 2 ramps leading up to the 2nd level but changed it only because it took away room from the bottom level. One was enough. Do whatever you like, you can always change it. I revised my cage a dozen times until it was perfect. your piggies will let you know what they like.

Also i would leave it on the floor. More sturdy. I tried adding grids to my as a base and the whole cage almost collapsed.

I made this "blue print" for you. It wouldn't let me type though. If you want to know what something is ask away

It didn't come up??

Where did you make this 'blueprint'

I made it under paint.