Im going to be re-doing mimzy's condo and browsed around the ideas here. I really like the layout of this one: http://i224.photobucket.com/albums/dd176/DellyKids/fd96e0027810ab8f0ee1225c9b81bd8f.jpg

But I noticed only 1 grid opens for the door at the bottom. I'm wondering how you would clean the upper levels if that's the only door that opens. (though it would be nice to only have 1 open) 

My question is, how can I make it to where 2 full columns of grids open in the front OR how can I make it to where only 1 opens to let her out but still be able to open a few top ones for easy cleaning? (hope that makes sense!)

This is how I made the doors on my condo. I ziptied wooden dowels on the grids that where the doors (note: I have two wooden dowels on the sides of the doors too for extra support)
Doors Closed

Doors open.

If you cut one of the wooden dowels shorter so one NIC cube didn't have it then that one would be free to just open and close but you could clip it to the others to make it one big door too! Does that make since?

Yes! Makes sense I actually just watched your video again on how you put yours together. I think I know how to do the doors now so thank you!

It's going to be a somewhat similar version of yours but smaller