Measure. Your. Room. TWICE.
For real, the immense amount of frustration you will feel if your new bed does not fit, will only be emphasized as you disassemble it then cry yourself to sleep on the floor. Oh, and do not forget about ceiling fan height too!
Keep ladder configuration and mattress thickness in mind!
Unless you can magically float to the top of your loft bed, you are going to want to pay attention to ladder configuration. Some styles have a fixed ladder that cannot be moved. This is a BIG deal when determining the layout of your space and which loft bed to purchase. And also, be mindful of how thick your mattress is versus the rails. We don’t want you going off the rails. Literally.
Plan ahead if you’re a hot sleeper.
Since hot air rises, you might be sleeping warmer in your loft bed. For those hot summer nights, put away the fleece blanket and consider attaching a small clip-on bed fan or installing an oscillating wall fan like this one.