Cat house out of fruit crates

I have three cats. And I'm a very light sleeper. Which means that I have to put the cats away for the night (otherwise they start running around like crazy when I turn the lights off). So at night they live in the bathroom. But we have heated floors there so I can't just put down a box or a soft house for them to sleep in.
So what did I come up with?
I walked around the house... And outside... And then in the garage (which I use to store stuff I don't need but don't want to throw away either), where I found these fruit crates!
I painted them white and made... kind of a bunk bed (flipped the first crate upside down so there's minimal contact with the floor and it won't overheat).

 

Easy! 

But the scariest part was yet to come. Will the cats use it?? Cats are known to ignore human effort and choose some random place to sleep in instead (one of my cats sleeps in the sink...).
But I was lucky this time and they use it every night!