Choose height, then plan the route up it
Chinchillas are mountain animals who live vertically when given the chance, so a tall cage with several levels suits them far better than a long, low one. Before fixing anything, sketch the route: a series of solid shelves and ledges staggered so the chinchilla climbs in short hops, never needing to leap a tall empty shaft or drop far onto a hard surface. Put the widest shelf partway up as a main resting and watching platform, with narrower ledges linking the levels on alternate sides. Leave the topmost area as a lookout perch rather than a place anything essential is stored, since the top is where a chinchilla will choose to sit, not where it should have to go to eat.
Materials that suit feet, teeth, and temperature
Use solid shelves of untreated, safe wood that a chinchilla can gnaw, fixed through the bars with washers so nothing rocks under a landing. Wire floors and mesh shelves are hard on feet and can trap toes, and plastic shelves will be chewed and can splinter into pieces a chinchilla may swallow, so both are poor choices for permanent fittings. A ceramic or marble tile on one shelf gives a cool resting slab in warm weather, which a thick-coated chinchilla will seek out. Everything in the cage should be treated as eventually eaten; if you would not want it chewed, it does not belong in a chinchilla cage.
Keep the ground floor for daily life
Arrange the floor level as the working part of the cage: hay in a rack or pile, a heavy food bowl that cannot tip, the water bottle at comfortable head height, and a solid hide house big enough to stretch in. Offer the dust bath as a scheduled visitor rather than permanent furniture, placing it on the floor for short bathing sessions and removing it afterwards so the dust does not coat every surface and irritate eyes and lungs with constant use. Deep, safe bedding across the floor cushions any missed landing from the levels above and gives some digging and foraging interest at ground level. A low shelf just above the floor gives a shy or elderly chinchilla a sense of height without any demanding jumps.
Furnish for chewing, hiding, and resting
Add chew sticks and safe wooden toys on different levels so travelling the cage has rewards at each stop, and expect to replace them as they are worked through. Provide at least one hide or covered corner on an upper shelf as well as the floor house, because some chinchillas prefer to sleep high and hidden. Avoid hammocks or fabric items that can be chewed into long threads, and check any fleece used for resting pads for pulled loops that could catch a leg. Keep the cage out of direct sun and draughts, in the coolest room available, since a tall cage in a warm room concentrates heat at the top where the chinchilla most likes to sit.
Set it up once, then keep it that way together
Photograph or note the finished arrangement before the first deep clean, including which shelf heights the chinchilla uses confidently and where the bath, bowl, and house belong. Rearranging everything at each clean unsettles an animal who navigates partly by habit, and can remove a step an older chinchilla relied on. Selected family members may open the chinchilla profile once access is shared under KinsLe Family Sharing.