Cats often enjoy having a quiet place to retreat, and a cardboard box can become a comfortable hideaway in less than an hour. This simple project uses inexpensive materials and can be adjusted for a kitten, an adult cat, or a larger, multi-cat household.
Materials and tools
Start with a clean, dry cardboard box that is large enough for your cat to turn around, lie down, and sit upright without feeling cramped. A box from a household delivery is usually suitable, provided it has not held chemicals, spoiled food, or strongly scented products.
You will need:
- One sturdy cardboard box with a lid or folding flaps
- A pencil, marker, or chalk
- A ruler or straightedge
- Scissors for thin cardboard or a utility knife for thicker cardboard
- Strong paper tape, masking tape, or packing tape
- A piece of cardboard for reinforcement, if needed
- A washable towel, fleece blanket, or small pet mat
- Optional: non-toxic paper, crayons, or removable decorations
Avoid staples, exposed wires, loose string, glitter, small detachable decorations, and adhesives with a strong lingering odor. If you use a utility knife, work on a stable surface and keep the blade pointed away from your hands. Children should have an adult handle the cutting.
Choosing the right box
The best box is sturdy but not so large that your cat loses the feeling of security. As a general guide, measure your cat from nose to the base of the tail, then choose a box whose longest inside dimension is at least that length plus several inches. The width should allow your cat to turn around comfortably, and the height should leave room to sit or crouch naturally.
Use these guidelines as a starting point rather than a strict formula:
| Cat or situation | Useful starting box size | Design adjustment |
|---|---|---|
| Small kitten | About 12 × 10 × 10 inches | Use a low, wide doorway and check frequently as the kitten grows |
| Average adult cat | About 18 × 14 × 12 inches | Add a medium doorway and one ventilation opening |
| Large cat | About 24 × 18 × 16 inches | Reinforce the base and make the entrance wider |
| Two cats sharing | Larger than an individual box | Add two exits so neither cat can block the other |
The box should not be so narrow that your cat becomes wedged inside. If your cat is elderly, has joint problems, or is recovering from an illness, choose a low entrance that requires minimal climbing or stepping.
Step 1: Prepare the box
Remove shipping labels, plastic film, loose tape, and any staples. Flatten or fold down the inside flaps so they do not hang into the sleeping area. Check every edge for sharp points or torn cardboard.
If the box has a strong perfume, cleaning-product, or food odor, choose another box. Cats rely heavily on scent, and an unfamiliar strong smell may make the hideaway less appealing. Let the box sit in a well-ventilated room before using it if the odor is mild.
Place the box on a flat floor and decide which side will be the front. If the cardboard feels soft, double the bottom by adding a second piece of cardboard inside or underneath the base. Secure it with tape on the outside whenever possible so your cat cannot chew loose tape.
Step 2: Mark the doorway
A rounded doorway is easy to draw and reduces sharp corners. Place the opening on one of the shorter sides of the box, leaving several inches of cardboard around it for strength. For an average adult cat, an opening approximately 8 to 10 inches wide and 8 to 10 inches high is often a practical starting point. Make it wider for a large cat or a cat that dislikes tight spaces.
You can create the shape with a ruler and a bowl:
- Mark the two vertical sides of the doorway.
- Place a bowl or cup at the top and trace part of its curve to form an arch.
- Check that the lower edge is high enough to retain the bedding but low enough for easy entry.
- Look at the drawing from your cat’s perspective and remove any unnecessarily narrow corners.
For a kitten, avoid making the opening so large that the box loses its structure. For a shy adult cat, a smaller entrance may feel more sheltered, but it must still permit easy entry and exit.
Step 3: Cut the opening safely
Cut along the marked line with scissors if the cardboard is thin. For thicker cardboard, use a utility knife and make several shallow passes instead of trying to force the blade through in one motion. Put a cutting mat or a scrap piece of cardboard behind the wall to protect the floor and prevent the blade from striking another surface.
After removing the doorway piece, inspect the edge carefully. Trim jagged areas with scissors, then cover rough edges with paper tape. Press the tape firmly so there are no lifted corners for your cat to pull loose.
Do not leave a long strip of tape exposed inside the box. If tape is needed on an inner seam, cover the entire seam smoothly and check it again after your cat has used the hideaway.
Step 4: Add ventilation and a second exit
Cardboard is breathable, but a closed box can still become warm or stuffy. Add two or three small ventilation openings near the upper sides or back. Make each opening large enough to provide airflow but not so large that your cat can get a paw caught. Smooth or tape the edges after cutting.
A second exit is especially useful when:
- More than one cat may use the hideaway
- Your cat is anxious about enclosed spaces
- The box is positioned near a wall or furniture
- You have a kitten that might panic if it feels cornered
The second opening does not need to be as large as the main doorway, but it should be genuinely usable. Do not place the box where furniture, blankets, or other objects can block the only exit.
Step 5: Strengthen the structure
Close the top flaps and tape the outside seams. Run tape along the bottom edges and across the main top seam, but do not create dangling strips. If the box flexes when you lift it, reinforce the base before your cat uses it.
A simple reinforcement method is to place a second piece of cardboard inside the floor. Cut it slightly smaller than the box interior so it lies flat without bending the side walls. You can also add a strip of cardboard along the inside of the roof, provided it does not reduce headroom or create a loose piece.
If you want a roof with a simple peaked shape, fold two opposite flaps upward and tape them together externally. Keep the interior smooth and leave enough height for your cat to sit comfortably. A flat roof is usually easier and safer for a basic hideaway.
Step 6: Make the interior comfortable
Add a thin, washable towel, fleece blanket, or small pet mat. Fold the bedding so it fits snugly and does not bunch up against the doorway. A thick cushion may reduce the available space and make the box unstable, so start with a thin layer.
Choose bedding that your cat already uses if possible. Familiar scent may make the new hideaway more inviting. Avoid loose stuffing, frayed fabric, cords, and materials that can wrap around paws or claws.
If the hideaway sits on a smooth floor, place a non-slip mat underneath it. Do not attach the mat with exposed adhesive inside the box. The hideaway should remain stable when your cat enters, turns, or exits.
Step 7: Introduce the hideaway
Place the finished box in a quiet area where your cat already likes to rest. Avoid putting it directly beside a loud appliance, busy doorway, radiator, or drafty window. Make sure your cat can reach it without passing through a place where it may be startled.
Let your cat investigate at its own pace. You can place a familiar toy nearby or scatter a few treats at the entrance, but do not push the cat inside or block the doorway. Some cats enter immediately; others may need several days before deciding the box is useful.
If your cat ignores the hideaway, try moving it to a different resting location. You can also remove decorations, replace unfamiliar bedding with a favorite blanket, or leave the top partially open. A cat may prefer a box that offers a clear view of the room rather than a fully enclosed shelter.
Simple customization ideas
Keep decorations lightweight, secure, and removable. You can create a playful theme without compromising safety:
- Draw windows, bricks, flowers, or simple paw prints on the outside with non-toxic crayons or markers.
- Add a cardboard roof overhang by attaching an extra panel to the exterior.
- Cut a few wide window shapes that do not weaken the corners.
- Make a removable name sign from cardboard and place it on the outside.
- Connect two boxes with a short, wide passage if you have enough space.
Avoid painting the inside unless the product is clearly labeled non-toxic and fully cured. Wet paint, strong odors, and peeling coatings can discourage use or create a hazard if chewed. Do not add ribbons, bells, feathers, beads, or small plastic parts that could be swallowed.
Troubleshooting common problems
The box collapses or tips over
Use a smaller box, reinforce the bottom, and tape the outside seams. Place it against a wall only if the wall does not block an exit. A heavier base can help, but do not add loose objects inside the box.
Your cat refuses to enter
Move the box to a familiar resting area, use familiar bedding, and leave the entrance unobstructed. Remove strong-smelling decorations and give your cat time. Never force a cat into the hideaway, since that can make the box seem threatening.
The doorway is too small
Enlarge it gradually with scissors, then retape the edge. The opening should allow your cat to enter without compressing its shoulders or rubbing hard against the sides. Check the doorway again if your cat gains weight or grows.
The hideaway becomes damp or dirty
Move it away from water bowls, litter trays, and damp floors. Replace wet or soiled bedding immediately. Cardboard is absorbent, so a box with urine, vomit, or persistent moisture should be discarded rather than repeatedly cleaned.
Your cat scratches or chews the cardboard
Some scratching and chewing is normal exploration, but remove the hideaway if your cat is swallowing pieces. Offer a cardboard scratcher nearby and inspect the box daily. Replace it when the walls become soft, torn, or unstable.
Safety and maintenance
Inspect the hideaway regularly, especially during the first few days. Look for chewed cardboard, loose tape, sharp edges, damp spots, insects, and collapsed panels. Replace the bedding when it is dirty and discard the box if it cannot be kept clean and dry.
Keep the hideaway away from candles, heaters, fireplaces, cooking areas, and electrical cords. Do not use it as a carrier or shut your cat inside. The hideaway should always be a voluntary resting place with a clear route out.
If several cats share the home, provide more than one resting option. A single box can become a source of tension if one cat guards it. Offer hideaways at different heights and in separate quiet areas when practical.
A simple cardboard hideaway works best when it is appropriately sized, stable, dry, and easy for your cat to leave. With a carefully cut doorway, smooth edges, comfortable bedding, and regular inspections, an ordinary box can become a useful retreat that is inexpensive to replace and easy to adapt as your cat’s preferences change.