WARNING: Readers have commented that this set-up is UNSUITABLE for rabbits, due to its size and material. For rabbit habitat requirements, please check out the following link for indoor rabbit housing requirements.
I made a 3-level indoor large rabbit hutch using a KALLAX storage unit from IKEA.
At the bottom level, where I placed the KALLAX door inserts, I sawed a hole at the side of the insert to allow an opening for the PVC pipe.
Then, I assembled the doors on the bottom as per IKEA instructions.
For the back, I drilled holes into two aluminium angles at the top and bottom, so I can slide in a piece of wood. This is so I can easily slide the back open for cleaning. I then screwed the angles to the top and the bottom.
Not pictured here yet but I am going to connect the PVC hoses between top floor holes to ensure there isn’t too much of a drop when jumping down a level.
Alternatively you could make the holes in the middle on the top floor off to the side so they don’t fall down a hole when jumping to the next section.
Hope the rabbit hutch is large enough for my bunnies.