My Plan to Build a Catio With an Automatic Cat Door Opener

Luna started crying halfway through my meeting.

Not meowing. Crying. The full baby-left-near-a-sliding-glass-door sound that makes people on a video call stop speaking and reconsider what kind of home office you are operating.

“That’s my cat,” I explained.

Luna looked at me and yowled again, louder this time, because apparently I had explained the wrong part.

Behind my laptop, Cali put her front paws on the table and then gently used one paw to nudge a pen toward the edge of my table. She kept eye contact the whole time. The pen rolled off and hit the floor.

Two cats. One request. Different communications teams.

The request was reasonable, which made it worse. The balcony was bright with sun. The condo was not. No useful sun patch reaches the floor inside, and both cats knew exactly where the missing sunlight had gone because they could see it through the glass.

My cats love the balcony, but I do not have an automatic cat door, so they cannot access it on their own. That is by design: I have not yet turned the balcony into a cat-safe, fully enclosed catio.

Any balcony catio sliding door plan only makes sense after the balcony itself is safe.

Luna handles this injustice out loud. Cali works through property.

I finished the meeting with one foot resting on the fallen pen so Cali could not send it farther into the administrative process. Then I looked at Luna. She walked over, pressed her forehead against my ankle, and immediately returned to the slider to resume negotiations.

Luna is very affectionate. She is also a cat who believes affection and compliance should be kept in separate departments.

Balcony time is currently an event

Balcony time is currently an event in our condo. I prepare the plan. The harnesses and leashes come out ready to be used if the cats are acting particularly feisty. The balcony is checked for dangers. Luna becomes impatient while I set up everything into place. Cali sits down halfway through the process as if she has been asked to wait at the DMV.

Then we all go outside together.

Luna checks the the corners, the furniture and the outside litter box. She’ll contemplate the railing and I’ll warn her before she agrees to settle into the sun. Direct sun pulls warm brown out of her black coat. She looks sleek and serious, like she has been assigned to survey the western border.

Cali walks three feet, finds the warmest section of concrete, and lowers herself onto it with the finality of a dropped beanbag.

There is already a standard litter box out there. Not an automatic one. My balcony has no electrical outlet, and even I have limits on how many engineering problems a litter box should create. The normal box works, Luna likes it, and it does not need firmware.

I stay outside with them because the balcony is not enclosed. When I come inside, they come inside. The slider closes behind us.

This routine gives them sun, fresh air, and a change of scenery. It also requires me to stop whatever I am doing and supervise the entire visit. If I leave the slider open, I am paying to air-condition the Santa Clara Valley. If I close it, Luna eventually reports the closure to management.

Their dream catio starts with the enclosure

So I’ve started planning their dream catio.

Turning a balcony into a catio sounds like one project. It has already split itself into twelve.

So far, “planning” has meant staring at the balcony and thinking, I could put netting there.

The project is already becoming a little more ambitious.

The concrete floor and existing railing make the space feel unusually ready for an enclosure. I am not trying to invent a balcony where none exists. I have the rectangle. What I need is a secure outer shell from the railing all the way overhead, with reinforced cat-proof mesh attached so carefully that Luna cannot locate one loose edge and turn it into her life’s work.

I have not solved the condo-permission part yet. I need to know what I am allowed to attach, what has to be reversible, and whether the building has opinions about my proposed feline penthouse. But in my head, the room is already taking shape.

Luna gets height.

She needs a waterproof cat tower with multiple levels, because putting one platform outside for Luna would be like giving a mountain climber a step stool. I want a high observation shelf where she can watch the parking lot, a middle shelf where she can judge birds, and a route between them that does not invite her anywhere near the top of the railing.

Cali gets width.

She is not asking for an advanced vertical curriculum. She wants a broad, stable platform in the direct sun, preferably large enough to rotate between her left side, her right side, and the position where she appears to have melted.

The tower has to be genuinely ready for weather, not an indoor cat tree that somebody placed outside and began referring to as outdoor furniture. The platforms need to stay stable. The materials have to tolerate sun and the occasional sideways rain. Nothing should wobble, soak through, or become lighter than the wind.

There also has to be shade.

This feels briefly disloyal to the cats’ stated objective, which is sun, but the dream catio cannot become a solar-powered griddle. I want a protected corner where they can get out of direct heat, fresh water in a stable spot, and a clear route back inside whenever they decide the weather has stopped meeting expectations.

The litter box needs its own sheltered area so rain cannot turn it into geology. The concrete floor needs to keep draining the way it already does. The mesh needs to stay tight around every edge. I want a scratching surface that can handle outdoor air, a few toys that will not become litter in the first gust, and one chair for me because I would still like to spend time out there with them. The goal is not to ban myself from the balcony. It is to stop being the required door hardware.

The door has to work for the cats

Somewhere in this process, I’ve realized the catio itself is only half the design.

The cats need a way into it.

Safe cat access to the balcony is part of the room, not an accessory I can solve later.

I’ve been thinking of it as a balcony catio sliding door problem. It is really an enclosure-first problem.

Once the balcony is fully enclosed, I do not need that doorway to identify Luna, reject Cali, or screen out a neighbor cat. There should not be outside animal traffic on the other side. Selective entry matters in plenty of homes. My problem is simpler: create a temporary passage into a contained room, then make the passage disappear again.

The obvious answer is a cat flap in a sliding-door insert. Before I get lost in tabs, the automatic pet door guide gives me the useful distinction: some devices move a flap, while others move the door. Then I picture Luna using one.

Luna likes being touched when Luna has selected the time, location, hand, and applicable terms. A flap brushing her whiskers or landing on her back might be completely fine. It might also become a permanent enemy after one attempt. I could train her gradually, hold the flap open, use treats, and let her decide at her own pace. What I cannot do is buy a flap and assume that because a hole exists, Luna will agree to move through it.

That is where the electronic-door idea starts to make sense to me.

I am effectively looking for a sliding door opener for cats who do not want to open anything themselves.

The smart pet door comparison is useful because I can sort every option by one Luna-specific question: does she push through something, or does the doorway get out of her way?

I’ve found a High Tech Power Pet patio insert whose panel lifts itself instead of asking the animal to push through it. I’ve also found the newer roll-up version, where the barrier moves up into the housing and leaves an open passage.

That is interesting because it solves the touching problem at the doorway. It also introduces a collar sensor, which is another object touching Luna. Every elegant solution eventually has to meet the cat.

Wayzn Smart Pet Door, which takes a different approach and moves the existing sliding glass door. No flap. No smaller pet opening. The slider opens, the cat walks through a normal doorway, and the slider closes again.

The Wayzn review keeps pulling me back to the unglamorous questions: whether my slider fits, how I would use it manually, and what happens when power or WiFi is not cooperating.

I want app control for the closing part

That is appealing to me, but not because I have been waiting for another app to manage. I do not need a chart showing that Luna requested the balcony seventeen times before lunch. I was present for the data collection.

I like app control because I want the opposite of what Luna wants. She wants a reliable opening. I want reliable closure.

If I am away from home, I want app control that lets me see the door is closed and, ideally, confirm the actual lock is secure. I want balcony access disabled when it should be disabled, and I want to know if the door has been left open or failed to close. A closed-door icon and a physically locked slider are not automatically the same thing, so I need a separate answer for the lock.

That has become one of my non-negotiable research questions. The final setup needs to protect the cats, preserve a safe way out for humans, sense an obstruction, and still let me shut everything down when nobody should be using it. If a device loses power or gets confused, I need a manual plan. If the cats are learning it, I need to be standing there.

I also still have to measure the slider and confirm what can fit. A patio insert takes up part of the opening. An opener that moves the existing door needs the right door configuration and enough track. Automatic return access may require a collar tag, which brings me back to Luna and her terms.

None of that is a reason to abandon the catio. It is the reason to design the whole thing instead of shopping for one impressive object and hoping the rest of the balcony organizes itself around it.

The enclosure comes first. Then the tower, the Cali-sized sun shelf, the shade, the protected litter box, the weather plan, and the route inside. Then supervised introductions. Then, if the measurements and security questions work out, an access system that opens without touching the cats and closes without donating the air conditioning to the neighborhood.

I have not built it yet

I have not built any of it yet.

For now, Luna still sits beside the glass and makes a sound that suggests a very small person has been denied legal counsel. Cali still watches my desk for unsecured objects. Balcony time still requires harnesses, leashes, and my full attendance.

But the project feels different now.

I am not trying to make Luna stop asking. I am trying to build a room worthy of the request.

Luna submitted the specification. Cali knocked it off the desk for approval.