The last one is my favorite, a little play house below the bunk bed is a genius idea.
I'm not a fan of bunk beds, but this is winning me over.
Quite possibly the most adorable play/day room I've ever seen
Custom Shiplap Bunk Beds with Built in Bench in Neutral Kids Room | Christopher Architects
Here's an interesting arrangement for built in bunk beds for three bunks to fit under an 8ft (244cm) ceiling. Click through to the website for more discussion on bunk beds and bedroom design.
Bunk room ideas @ House Remodel Ideas
13 clever ways to fit three kids in one bedroom
Sumptuous triple bunk beds in Kids Rustic with Rustic Cabin Bunk Bed next to Bunk Beds With Desk alongside Blue Area Rug and Kid Room Colors