Catio access from the house

Choose the route before the enclosure

Start with the opening you can use, then decide where the catio belongs. Catio Spaces identifies windows, walls, patio sliding doors, and wood doors as access routes. Its placement guidance notes that choosing an insert instead of cutting through a wall or door can affect where you build.

A removable window or patio-door insert suits a setup where you want to restore the opening later. A wall- or door-mounted flap requires cutting, so it is the wrong route if you cannot alter that surface. A tunnel can connect the house to a more distant enclosure, but you still need a compatible opening at the house.

• Window insert: match the insert to the window’s opening direction.
• Wall or door flap: plan for a permanent cutout.
• Sliding-door panel: check the frame height and track compatibility.
• Tunnel: plan the house connection and the route to the enclosure together.

Window inserts: fit, measurements, and cost

Habitat Haven calls its insert for an up-and-down sash window a horizontal insert; its vertical insert fits a window that slides side to side. Both styles use 3/8″-thick polycarbonate. Do not choose by the product name alone: match it to how your window moves.

For a horizontal insert, Habitat Haven says to measure the opening width with the window raised and add 1/2″. For a vertical insert, measure the opening height plus the depth of one window track. Habitat Haven says its inserts are custom-made and non-refundable, so confirm measurements before ordering.

Prices were checked in October 2026. The window-insert seller lists its made-to-order window insert at a regular price of $189.99 and says size customizations may cost extra. Habitat Haven says widths over 60″ require custom-ordered polycarbonate or PVC, increasing price and lead time.

• Without a tunnel attachment: Habitat Haven’s horizontal insert is 13″ high; its vertical insert is 13″ wide.
• With a tunnel attachment: those dimensions increase to 18″.
• Included door: 9-1/4″ wide x 10″ high, with a 7″ x 7″ flap.
• Cat fit: Habitat Haven specifies up to 14″ at the shoulder and an approximate maximum weight of 16–20 pounds.

Inserts, doors and units with listed details

What the seller lists	Seller
Standard inserts without tunnel attachments are 13 inches high for horizontal windows and 13 inches wide for vertical windows.	Habitat Haven
The included cat door measures 9-1/4 inches wide by 10 inches high, with a 7-by-7-inch flap.	Habitat Haven
The standard pet door is designed for cats up to 14 inches at the shoulder, with an approximate maximum weight of 16–20 pounds.	Habitat Haven
Each additional two inches beyond the standard 4-inch tunnel costs $20; an 8-inch tunnel adds $40.	Habitat Haven
Window cat door insert: The listed regular price is $189.99.	PFPurrfect Fence
Window and patio sliding-door cat doors are removable and do not require cutting the window glass.	Catio Spaces
Cat doors range from under $100 to several hundred dollars, depending on type, size, and security options.	Catio Spaces
PetSafe offers sliding glass pet door panels in 81-inch and 96-inch sizes.	PPetSafe
Five flap sizes are available, covering small cats up to 15 pounds through extra-large pets up to 220 pounds.	PPetSafe
Porch Perch catio: A sliding glass door provides direct entry for cats, and a human-sized door is optional.	Cat Topia

Details as listed by each seller on Oct 9, 2026. Measure your window or door opening before ordering.

Door, wall, and sliding-panel access

A cat door in a wall or exterior door uses a frame and flap fitted into a cut opening. Catio Spaces says to check a proposed wall location for wiring or piping before installation, then follow the manufacturer’s template and installation guide. For floor-level access, it recommends placing the bottom of the flap approximately 4″ above the floor.

For a catio beside a sliding glass door, a track-mounted panel avoids cutting the existing glass. PetSafe offers 81″ and 96″ panels made with weather-resistant aluminum, tempered glass, and magnetic closures. PetSafe says its panels use adjustable brackets without drilling or cutting, while keeping the human sliding door functional.

Measure the sliding-door frame height, then check the specific door type and any recessed-frame requirements against the listing. PetSafe says to choose the flap using your cat’s weight and dimensions, not panel height alone. Catio Spaces gives a broad cat-door price range from under $100 to several hundred dollars, depending on type, size, and security options; check the selected panel’s listing for its current price.

Line up the outdoor connection

Match the enclosure’s entry point to the house opening before settling its position. Catio Spaces’ Window Box uses wood angle support braces attached to the house and fits sliding and sash windows. It can also sit entirely below the sill when access comes through a wall-mounted cat door, so window access is not the only arrangement.

For a catio farther into the yard, Catio Spaces offers an 8′ Cat Tunnel plan that can follow the house or yard edges with elevation changes. Habitat Haven’s window-insert tunnel attachment is a shorter connection: the included length is 4″, with attached tunnels available up to 12″. Habitat Haven charges $20 for each additional two inches; an 8″ attachment adds $40.

• Check where your cat will step out, and plan any landing, shelf, or ramp around that opening.
• Habitat Haven says its tunnel connector requires an 18″-high insert and a window that opens at least 18″.
• If the porch is your main entrance, Catio Spaces recommends placing the catio beside the main door rather than across visitors’ route.

Control access and reduce drafts

Treat the cat flap and the house opening as separate security checks. Habitat Haven includes a 4-way locking pet door; Catio Spaces also describes manual locks, electronic microchip options, and interior lock-out panels. Check which controls the selected door actually includes rather than assuming every flap has the same features.

For the compression-frame inserts Catio Spaces describes, an interior knob holds the unit in the existing frame channel. Its installation instructions call for fitting the unit, tightening the knob, and closing the window against it. Catio Spaces says a wood dowel in the remaining channel can prevent the window or patio door from opening farther; removing the insert allows the opening to return to its original position.

Weather-stripping addresses the gaps around the insert and flap. Habitat Haven includes an adhesive foam strip for the insert and a thicker foam strip for the window track; the window-insert seller describes brush weather-stripping on the flap and foam around the insert. Catio Spaces says a lock-out panel adds insulation to an unused single-flap door, while wall-mounted doors can use interior and exterior flaps for another insulation layer.