Installing a cat door in an interior bedroom door means measuring your cat’s shoulder height, cutting a template opening with a jigsaw, then clamping the two frame halves together and hand-tightening the screws.
Whether you can install a cat door in an interior door depends on one thing first: the door itself. A solid wood or composite door handles a cutout fine. A thin hollow-core door can work, but it flexes, and the frame has less material to bite into.
Here’s the sequence the official PetSafe guides repeat across their models: pull the door off its hinges, measure your cat, trace and cut the opening, test-fit both frame halves, then screw them together from opposite sides. The whole job runs on one afternoon with a jigsaw, a drill, and a template.
What You Need Before Cutting Anything
The right tools matter more here than on most projects, because you only get one shot at a clean cut. Gather everything first so you’re not stopping mid-cut with a jigsaw running.
- A jigsaw with a fine-tooth blade for the door material
- A drill with a 3/8-inch bit for the corner holes
- The template that ships with your cat door
- Painter’s tape, a pencil, and a level
- Sawhorses or a workbench to lay the door flat
- A screwdriver — hand-tightening only, no power driver
- Caulk, only if your door’s instructions call for it
PetSafe’s guidance for the Electronic Pet Door in a Door is specific about this step: take the door off the hinges and lay it on sawhorses before you cut. A door that shifts mid-cut gives you a crooked opening, and a crooked opening means the frame halves won’t seat.
Measuring Height And Placement
Your cat’s shoulder height sets the placement, and PetSafe’s guides use that measurement as the reference point — one says the top of the template should sit at your marked shoulder-height line, while PetSafe’s wall-install guidance adds 5 inches to the shoulder measurement. For a door install, follow your specific model’s template instructions.
Stand your cat on level floor and measure from the floor to the top of the shoulder blades, not the head. Mark that height on the door. Then tape the template in place, align the center and height lines, and check it with a level — off-center placement is the most common reason a cat refuses to use a new door.
Cutting closer than that weakens the door around the opening.
Cutting The Opening Step By Step
- Lay the door flat on sawhorses, with the side you’ll mark facing up.
- Tape the template down and trace its outline in pencil.
- Drill a 3/8-inch hole at each corner of the traced outline.
- Feed the jigsaw blade into a corner hole and cut along the line, supporting the waste piece as you go.
- Test-fit the interior and exterior frame halves in the opening. If the fit is tight, make adjustment cuts before you assemble anything — PetSafe says to adjust rather than force.
- Insert the screws and tighten by hand. PetSafe’s guides warn against overtightening, which can crack or deform the frame.
- Caulk the gaps around the frame if your model’s instructions call for it.
Use the screws that came with your door, or trim them to match your door’s thickness. Screws that are too long can punch into the frame or through the door face.
When it’s done right, the two frame halves sandwich the door skin with no wobble, and the flap swings freely without scraping the sides.
Model Differences And Common Mistakes
PetSafe’s install sequence is nearly identical across the Electronic Pet Door in a Door, the Extreme Weather Aluminum Pet Door, the Deluxe Pet Door, the Freedom Door, and the Plastic Pet Door — measure, cut, test-fit, screw together. The differences show up in materials and features, not the cutting method.
One important gate: PetSafe also publishes a guide for the Microchip Cat Door in a metal or metal-core door, and that guide is for metal doors. Don’t use it as your primary reference for a typical wooden or composite bedroom door. It solves a different problem.
By far the most common mistake is cutting without taking the door off its hinges. The second is reaching for a drill to drive screws. Any one of those three turns a clean install into a repair job.
If you’re still deciding which model is right for your cat before you cut, browsing our tested bedroom cat door picks can narrow the options. And before you commit to a model, you can read PetSafe’s install guide for the Electronic Pet Door in a Door, which states the same core sequence for a standard door install.
FAQs
Can I cut through a hollow bedroom door?
Yes, and it’s done often. A hollow-core door has a thin outer skin and a cardboard honeycomb inside, so the opening needs to land between studs of internal framing rather than on one. Use a fine-tooth blade, cut slowly, and keep the 3-inch margin from the door’s edges for stability.
How big should the opening be for my cat?
The opening is set by the door model you buy, not by custom cutting. Match the model to your cat’s shoulder height and weight, then use that model’s template. A flap that’s too small gets avoided; one that’s too large lets weather and drafts through in exterior setups.
What if the frame halves don’t fit after cutting?
PetSafe’s guidance is to make adjustment cuts rather than force the halves. A cutout that isn’t square is the usual cause. Recheck that your corner holes were drilled at the traced corners, not inside the line, and shave the opening in small passes until both halves sit flush.
References & Sources
- PetSafe. “How to Install the Electronic Pet Door in a Door” Source of the remove-door, cut-on-sawhorses sequence and the 3-inch margin rule.
- PetSafe. “How to Install the PetSafe Extreme Weather Aluminum Pet Door” Confirms the recurring frame-and-screw install method across models.
- PetSafe. “How to Install the PetSafe Microchip Cat Door in a Metal or Metal Core Door” Metal-door guide, referenced here as a different install case.
