A catio — a contraction of ‘cat’ and ‘patio’ — is an outdoor enclosure that allows indoor cats to experience the sights, sounds, and smells of the outside world in complete safety. For the millions of cats that spend their lives entirely indoors, a catio can be a life-changing addition that dramatically enhances mental and physical wellbeing. For cat owners, a catio offers peace of mind: the freedom to give their cat outdoor access without the risks that come with unsupervised outdoor roaming.
Catios range from simple window-mounted box enclosures to elaborate multi-room garden structures connected to the home by enclosed tunnels. Whatever their size or complexity, they share the same purpose: providing a secure, enriched outdoor space where cats can engage with their natural environment on their own terms.
Why Catios Matter for Indoor Cat Wellbeing
Indoor cats live longer, safer lives than outdoor cats on average — protected from cars, predators, diseases, and toxins. But indoor life comes with its own costs. Cats are natural hunters with strong territorial instincts and powerful needs for sensory stimulation. An under-enriched indoor environment can lead to boredom, obesity, stress-related conditions like feline idiopathic cystitis, anxiety, and behavioral problems including destructive scratching, excessive vocalization, and house-soiling.
Outdoor access through a catio addresses these needs directly. Studies and behaviorist observations consistently show that cats with access to enriched outdoor environments show reduced stress behaviors, increased activity levels, and greater overall contentment. The complex sensory experience of being outside — changing light, natural sounds, air movement, the smell of grass and rain — provides stimulation that no indoor environment can fully replicate.
Catios also benefit multi-cat households by providing additional territory and space, reducing competition and tension that can develop in enclosed indoor environments. For cats that have spent time outdoors previously and been transitioned to indoor-only life, a catio can ease the adjustment significantly.
Types of Catios
Catios come in several broad categories, and choosing the right type depends on your available space, budget, and your home’s layout:
Window box catios: The simplest and most compact option. Mounted directly over a window opening, these small enclosures allow cats to sit outside the window in a safe mesh enclosure. Ideal for apartments or homes with limited outdoor space. Some designs are completely external; others require a cat door or modified window screen for access.
Lean-to catios: Larger structures built against the exterior wall of the house, accessed through a cat door or modified window. These can range from a few square feet to the size of a small shed and are popular for their space efficiency and relatively straightforward construction.
Freestanding catios: Independent structures placed in the garden, connected to the house via an enclosed tunnel (often called a ‘catwalk’). These offer the greatest flexibility in placement and can be very large and elaborate. They are ideal for homes with garden space and for owners who want to create a true outdoor sanctuary.
Tunnel systems: Networks of enclosed mesh tunnels that run through the garden, allowing cats to explore a larger area safely. Often combined with a central freestanding enclosure, these systems give cats a sense of range and exploration while maintaining full security.
Building or Buying a Catio
Catios can be purchased as pre-made kits or built custom from scratch. Both approaches have merits.
Pre-made catio kits: Available from specialist manufacturers, catio kits come with pre-cut lumber, hardware cloth, and detailed instructions. They reduce the complexity of building from scratch and are available in a range of sizes. Brands such as Catio Spaces, Outback Jack, and various Etsy vendors offer popular kit options. Assembly typically requires basic tools and a few hours of work.
DIY builds: Building a catio from scratch allows complete customization of size, layout, and features. The key materials are treated or cedar lumber for the frame, hardware cloth (welded wire mesh with 1” x 1” or smaller openings) for the walls and roof, and appropriate fasteners. Detailed free plans are available from numerous catio-focused websites and communities. A DIY approach can halve or more the cost of a pre-made kit for a comparable structure.
Professional custom builds: For large or complex catios, hiring a contractor — especially one with experience in catios or custom outdoor structures — produces the most polished result. Some areas have catio specialists who design and build entirely custom enclosures.
Enrichment Inside Your Catio
The physical structure is only part of what makes a catio valuable. The enrichment items within it determine how much your cats actually use and enjoy the space. A well-enriched catio gives cats meaningful things to do at every level:
Vertical space: Cats feel most secure when elevated. Include shelves, perches, and climbing structures at multiple heights. A shelf near the top of the enclosure will almost always become the favorite resting spot.
Cat-safe plants: Cat grass (wheat or oat grass), catnip, valerian, rosemary, and lavender are popular choices. Avoid toxic plants including lilies, sago palms, and azaleas. A small raised garden bed planted with cat-friendly herbs provides foraging and chewing enrichment.
Scratching surfaces: Include horizontal and vertical scratching options. Logs, rough bark, and sisal-wrapped posts all work well and complement the natural aesthetic of an outdoor enclosure.
Wildlife viewing: Position the catio to maximize viewing of birds and other garden wildlife. A bird feeder or birdbath placed just outside the mesh gives cats hours of entertainment without endangering local wildlife.
Weather protection: Ensure at least part of the catio has a solid roof for shade and rain shelter. Add cozy bedding in a covered corner so cats can stay comfortable in variable weather.
Safety Considerations for Catios
A catio is only as good as its security. Construction and ongoing maintenance should address these key safety factors:
Use hardware cloth with openings no larger than 1” x 1” — larger openings can allow cats to partially squeeze through or allow small predators (such as snakes) to enter. Secure the mesh firmly to the frame with staples and u-nails, and cover all edges with wooden battens to eliminate sharp wire ends. Ensure the base of the enclosure cannot be dug under by predators or escapees — bury the mesh edge or lay a mesh apron along the ground.
Inspect the catio regularly for damage, rust, or weak points in the mesh. Plants inside the catio should be verified as non-toxic before planting, and any fertilizers, pesticides, or garden chemicals near the catio should be avoided. Ensure multiple safe exit routes exist so a cat is never cornered if startled.
Finally, introduce your cat to the catio gradually. Some cats, especially those that have been strictly indoor for a long time, may be initially hesitant about the outdoor environment. Let them explore at their own pace, use high-value treats to build positive associations, and allow them to return indoors whenever they choose.