Convert a Window, Porch, or Patio into a Catio (Cat Enclosure)
Window, Porch, Deck, or Patio → Catio (Outdoor Cat Enclosure)
Build a catio — an outdoor cat enclosure — off a window, porch, deck, or patio that lets your cat safely enjoy fresh air, sunshine, and outdoor enrichment while protecting them from traffic, predators, and other dangers, and protecting local birds and wildlife from your cat.
Cost Range
$200 – $5,000
Timeline
1–3 weeks
Materials Cost
$1,630
Permits Cost
$100
Steps
Choose Your Catio Type and Size
Catios range from tiny window boxes to elaborate garden enclosures. Choose based on your space and budget. A window box catio is the most compact option — a small enclosure mounted to an exterior wall that your cat accesses through an open window, perfect for apartments and small spaces ($200 to $600). A porch or patio catio encloses an existing covered porch, deck, or patio area with screening or mesh, giving your cat a generous space while reusing structure you already have ($500 to $2,000). A freestanding garden catio is a larger standalone enclosure in the yard, often connected to the house by a cat tunnel ($1,500 to $5,000). For most cat owners, enclosing part of an existing porch, deck, or patio offers the best balance of space and cost.
Estimated time: 2 days
Pick the Best Location
Location dramatically affects how much your cat enjoys the catio. Cats love the sun, so choose a side of the house with part to full sun (you can add shade cloth for hot afternoons). Pick a spot with stimulating views — an expansive garden, a bird feeder area, or family activity keeps cats fascinated for hours. Avoid locations with alarming noises like a neighbor’s constantly barking dog, a loud air conditioner unit, or a driveway where cars pull in and out, as these can cause your cat to avoid the space. Also consider how your cat will access the catio: through a window, a wall-mounted cat door, or a door leading to the porch or patio.
Estimated time: 1 days
Check Local Regulations and HOA Rules
Before building, check local regulations. Some jurisdictions require structures like catios to be set back a certain distance from property lines, especially freestanding enclosures. If you live in an HOA, review the rules — some restrict exterior structures or require architectural approval. If you rent, get written permission from your landlord before attaching anything to the building. Most window box and porch catios are simple enough to avoid permit requirements, but larger freestanding structures may need a permit depending on size and your local code. A quick call to your building department clarifies what applies.
Estimated time: 2 days
Plan the Cat Access Point
Your cat needs a safe, easy way to get from inside the house into the catio. Options include an open window with a secure frame (the cat hops through an always-open window into a window box catio), a wall-mounted pet door (a cat flap installed through an exterior wall — the most permanent and weatherproof option), a window-mounted pet door (a cat flap installed in a window insert, ideal for renters since it does not modify the wall), or an existing door to a porch or patio (simply prop or install a cat door in the door to the enclosed area). Plan this access point before building so the catio connects seamlessly to your cat’s indoor space.
Estimated time: 2 days
Build the Frame
Build the catio frame from weather-resistant lumber (cedar or pressure-treated pine) or use a metal frame. For a porch or patio enclosure, you may be able to use the existing posts and railings as part of the structure, adding framing only where needed to support the mesh. For a freestanding or window box catio, build a complete frame sized to your plan. Ensure the frame is sturdy and securely anchored — to the house for attached catios, or to the ground or a solid base for freestanding ones. The frame must be strong enough to keep predators out and your cat safely in. Seal or paint the wood to protect it from weather and to complement your home.
Estimated time: 3 days
Install Escape-Proof and Predator-Proof Mesh
The mesh is the most critical safety component. Use galvanized welded wire mesh or heavy-duty screening rated to keep cats in and predators out. Standard window screening is NOT strong enough — a determined cat or a raccoon will tear through it. Use welded wire mesh with openings small enough that your cat cannot squeeze through (1 inch by 1 inch or smaller) and strong enough to resist clawing and chewing. Secure the mesh to the frame with staples, screws and washers, or furring strips for a tight, gap-free attachment. Pay special attention to corners, the roof, and any gaps where a cat could escape or a predator could enter. A polycarbonate or mesh roof provides weather protection and prevents climbing escapes.
Estimated time: 3 days
Add Cat Enrichment Features
A great catio is not just safe — it is enriching and fun for your cat. Add vertical elements since cats love height: shelves and perches at multiple levels, ramps and steps connecting them, and a cozy elevated nap spot or hammock. Include scratching posts (a vertical post or a section of the frame wrapped in sisal rope) to keep claws healthy and let cats blow off steam. Add a climbing tree, branches (natural birch or other safe wood), or cat-safe platforms for adventure. For sensory enrichment, place the catio near a bird feeder (positioned so cats can watch but not reach birds), add cat-safe plants like catnip or cat grass, and include a cozy enclosed hideaway cave. The more vertical space and enrichment, the more your cat will love and use the catio.
Estimated time: 2 days
Add Comfort, Weather Protection, and Final Details
Finish the catio for year-round comfort and safety. Add shade with a shade cloth or a solid roof section so your cat can escape the hot sun. Provide weather protection so part of the catio stays dry during rain. Include a comfortable resting spot with a weatherproof cat bed or cushion. Ensure fresh water is available, especially in warm weather. Add flooring that drains and cleans easily — many catios use the existing deck or patio surface, outdoor carpet, or artificial turf for a grass-like feel. For larger catios, consider adding a human-sized door and a seat so you can join your cat in the space. Do a final safety inspection: check every mesh seam, corner, and gap to ensure there is no way for your cat to escape or for a predator to get in. Once secure, let your cat explore their new safe outdoor sanctuary.
Estimated time: 2 days
Materials
| Material | Est. Cost | Required |
|---|---|---|
| Weather-Resistant Lumber (cedar or treated pine) | $400 | Required |
| Galvanized Welded Wire Mesh (1 inch or smaller) | $250 | Required |
| Polycarbonate Roof Panels or Mesh Roof | $200 | Required |
| Cat Door (wall-mounted or window-mounted) | $60 | Required |
| Mounting Hardware (screws, staples, washers, brackets) | $60 | Required |
| Wood Sealant or Exterior Paint | $60 | Required |
| Shelves and Perches (lumber) | $150 | Required |
| Ramps and Steps | $100 | Optional |
| Scratching Post / Sisal Rope | $40 | Required |
| Cat Hammock or Elevated Bed | $40 | Optional |
| Climbing Branches or Cat Tree | $80 | Optional |
| Shade Cloth | $40 | Optional |
| Cat-Safe Plants (catnip, cat grass) | $30 | Optional |
| Outdoor Carpet or Artificial Turf | $80 | Optional |
| Weatherproof Cat Bed | $40 | Optional |
Permits
Building Permit (larger structures)
Window box and small porch catios usually do not require permits. Larger freestanding catios may require a permit and must observe property-line setbacks. Check with your local building department and HOA.
$100