Sometimes the glitch of placing windows trough walls occurs.
You have the best chance of accessing the glitch by selecting a window object on the lobby/floor of your hotel.
place an empty layout on an empty floor and put a door in it. This isn't nessicary for the glitch to occur but it gives the best chance of recognizing it.
Go to perspective cam and 'walk' into the empty room. turn around a bit so you can look into the floor of your hotel.
Now you will probabily see some blue spikes on either side of the door. If you don't, try moving around a bit.
Reason for the glitch to occur: The game doesn't draw what the player can't see to make the game faster. However, some calculation mistakes like flooring multiple-decimal answers may cause a slight difference in the eventual outcome of the calculation, plus it draws only whole tiles, which makes the blue spaces in the floor look like spikes on the door.
This glitch can also occur when walking trough walls, which is not a glitch itself, into a stuffed room: if you are 'standing' in an object like a back bar or vending machine you can look trough it but because of the same calculation mistakes the game will remove any objects so it looks like an empty layout.
Put a light in the blur area and you will some carpet (Land), keep doing that and you will get a lot of land *Smile*