Catios Keep Cats and Birds Safe

Born to a homeless mom, Swirlee and his siblings were brought to us at about 12 weeks of age to be socialized so that they could be placed in homes, rather than live difficult lives outdoors. We adopted Swirlee, now 10 years old (in 2024), and as his personality emerged — from quiet, shy kitten to outspoken king of the castle — a catio proved to be indispensable.

What’s a “catio” and why would you want one?
A catio is an outdoor enclosed patio for cats (and sometimes their caregivers), where they can enjoy the sights, sounds, and smells of the outdoors without getting into trouble. While catios can’t provide total freedom, they prevent Kitty from getting hit by a car, being badly injured or killed by wildlife such as coyotes, acquiring fleas and all the diseases that can result from them, fighting with other cats, and upsetting neighbors who don’t like cats. They also lessen indoor-only cats’ chance of getting feline hyperthyroidism (an increasingly common feline disease caused partly by exposure to chemicals in the dust from flame retardants in bedding and electronic devices), relieve boredom, and assist in multiple-cat households when cats need their space or just a nice place to nap. Last — but definitely not least — catios help keep birds and other little wild creatures safe. Especially if you use bird feeders and/or have a “real” garden designed to attract and support wildlife, allowing your cat to roam freely creates an “ecological trap” that invites disaster, particularly when they are young or seem born to kill. New research has documented just how bad it is.

Most wild bird species — even those considered somewhat common — are in trouble and while predation by cats is certainly not the only cause of birds’ population declines, it is reportedly the leading cause of injury for wild animals treated at Audubon’s Wildlife Care Center in Portland, accounting for nearly 40 percent of intakes; numbers are likely similar at other wildlife rehabilitation facilities. Domesticated cats are predators and obligate carnivores and, despiteyellow warbler migrant their domestication, most yearn to stalk and kill prey—we can’t blame them; it’s in their DNA. Since we are ultimately responsible for our cats and their actions, it’s our responsibility to keep them indoors but also to think about their needs by offering a place to lie in the sun, breathe some fresh air, and watch a little slice of the world.

Of course, expecting a cat who has always been allowed to roam freely to suddenly agree to stay indoors may be asking too much (no matter how exciting the catio may be!). We were privileged to have had the opportunity to rescue and adopt a Katrina Kitty in 2005 who yearned to go outside (as he had at his previous home); we caved in to his demands, but only for fairly short periods mid-day when birds are least likely to be foraging, never during baby bird season, and never at night, but he did kill some birds and rodents. But young cats who are new to your household and those who have never experienced the outdoors are ideal candidates for the catio life. We have several other rescued cats and our catio is crucial for meeting their outdoor needs—they love it, especially on warm, sunny days. Even our newest rescue, Caspurr, an older gentleman who had been outdoors on his own for who-knows-how-long (probably abandoned), is very happy that we have a catio. [Update 4/2022: With great sadness, we were forced to put Caspurr to sleep last month. Fast forward a month: an unwanted, neglected, all-white kitty, now named Swan, was welcomed into our home. Swan had also been in the habit of going outdoors whenever he pleased, but he seems quite happy with just the catio.]

Many choices
There are many different types of catios, from fairly inexpensive window boxes that cost less than $100, to more expensive and elaborate designs that may include catwalks, tunnels, roofs, furniture and multi-levels (the latter is essential!). Some people design and build their custom catio themselves, as my husband, Rick, and I did, while others hire a contractor or handyman. Kits to build your own are available online. For more detailed guidance and tips, as well as links to companies that sell kits, check out this article from The Humane Society of the U.S.

Before renovation–can you say “ugly”?

When we initially thought about making a catio, we considered turning half of our elevated deck into one, but it would have been very difficult and there was no way for the cats to come and go on their own—that is, no place to install a little cat door.  Our cats really love our deck, but some of them cannot be trusted not to leap eight feet to ground level. We once tried stretching some plastic netting (which I strongly frown upon) across half our deck, but it became dangerous when our little Violet got a claw caught in it and dangled in mid-air! Luckily I found her soon after it happened.

One day, it hit me: Why not turn a mostly unusable space on the east side of our house into a space for the cats? When we bought our house I thought it could be made into a little sunroom, but a catio wouldn’t require heating and insulation and such, and our house didn’t need to be any bigger.

A little history: When our house was built in 1929, there had been an exterior wooden porch, about 13 feet long by 7 feet wide, with two doors to the inside at either end. Twenty to thirty years later (in the 1950s, judging by the type of brick) someone put a concrete floor over the wooden floor and created narrow planters made with brick and mortar, and installed a huge floor-to-ceiling window and sliding glass doors. Sometime later, the space was enclosed to make it into a greenhouse of sorts, with translucent fiberglass panels for walls and roof; the planters were covered with formica (see photo above). But functionality as a greenhouse was poor: Summer temperatures soared well over 100º because ventilation was nonexistent when the exterior door was closed, and it was very cold during winter. Plus, the old fiberglass had yellowed, the carpet was filthy, and the sliding glass doors and window that covered the interior wall were single paned and very energy inefficient (and they looked awful in an older home). Renovating the space would help increase energy efficiency in our house,  provide us with a much more useable space and keep our cats happy.

The Casbah Catio
Since we did everything ourselves, it took about 5 months (of mostly weekend work) to complete, not counting the time it took to replace a window and door; during the winter months things were put on hold. Rick did the majority of the planning and work; I helped with tiling and did most of the painting (and gave moral support!). We were able to reuse some of the wood from the old structure, and some came from our local Rebuilding Center, which sells reclaimed materials (I love that place!), but we did have to buy a fair amount of new materials. Huge rocks that had been buried in the planters found better homes in the garden.

I’ve always loved the design of northwestern Africa and I was finally able to sneak some elements into this catio. The tile came from the outlet room of Pratt and Larson in SE Portland; selection varies and I think we made at least five trips there to find what would look good together. At $1 a pound, it was a great deal.

Initially, the most important task is planning. Some suggestions: (1) Try to site it where the cats will be able to see things of interest; (2) think about how the cats will be able to get in and out (it’s best to connect it to the main house because if you have to carry your cat to and fro, it may get little use after the novelty has worn off); (3) consider how you will keep it dry so it can be used year-round; and (4) be sure to give cats variety, including some elevated places to perch, cushy places to snooze, a litter box, and scratching posts. Make some sketches and draw up a basic plan. If you are going to do any demolition, be sure to figure out where you can take items (like old carpet or glass) to be recycled, rather than just throwing it in a landfill.

Here’s a basic synopsis of how we turned an unusable space into our catio: First, we removed the existing glass doors and window (and carefully smashed them up to transport to a recycler; the metal frame also was recycled). The wall was then framed in and a new, large window (that closely resembles an original window in our living room) and a door that enters our dining room were both installed. Next, the new window, door and areas below were covered and demolition began.


Demolition Days (boyz just love to wreck things, don’t they?). Actually, we both hated this part (it was definitely the most difficult and dirtiest part—a huge mess, as you can see). Rick’s definition: “Grunt work.” We left the existing concrete foundation (beneath the brick) even though it wasn’t built well to begin with.


The original porch floor had never been connected to house, so that had to be fixed; we also dealt with some rot in a sill plate where a door once stood. Following that, 4x4s were added and walls were framed in. Painting was done as things progressed. Although I hate using plastic, because we wanted natural morning light to enter the catio and the house’s window and door, we chose a roof of clear, corrugated polycarbonate outdoor patio cover (lightweight, easy to install, inexpensive)._MG_8965

An outer door that leads to the back yard was then installed and we chose DIY screens to keep the cats in. Most people use a large metal mesh, but we chose recyclable aluminum screen (not nonrecyclable plastic), for several reasons: First, a few years earlier, two small immature birds had entered our house through a very small opening one morning and were immediately caught and killed by our cats; we feared this could happen with the large mesh. There is smaller mesh available, but it’s difficult to see through. Window screen, on the other hand, almost disappears from view after installation. Second, we like to have the door that connects the catio to our dining room open during nice weather and we wanted to keep insects out, and keep our cats from killing them. Of course, screen is shreddable by claws and it gets dirty, but for the most part we’re happy with it. (However, if I were to do it all over again I would opt for screens that could be removed for easy annual cleaning.) If the screens ever get completely shredded, it’s not very difficult to replace (and recycle) them. Whatever you do, don’t use plastic mesh.

Speaking of doors, we wanted a cat door so the cats could come and go as they pleased, but we were concerned about cold drafts during the winter. Rick installed a Freedom Pet Pass door, an energy efficient flap door. The only thing that’s problematic is that because our two formerly feral female cats are tiny (only about 7 or 8 pounds) and scare easily, they have trouble pushing the door outwards due to a fairly strong magnet; they usually manage by pulling it inward with their claws unless we come to their rescue. Coming inside requires less force, so that isn’t a problem for them. The door is visible at the lower left corner of the final photo, below. We usually have it propped open for the cats when the outside temperature is above 62ºF or so.

Levels are absolutely essential for felines, who often make their living by observing prey below. We placed them so they could easily hop from one to another. My cats highly recommend varied levels for bird and squirrel watching!          

Lovely Violet (now age 16), who came to us as a 5-month-old feral kitten, loves levels …


Luna, too!

Luna, now 14, another rescue, also loves levels, and naps in the catio on warm days.


We also added a bench at the far end that offers some storage space and seating.

tile backer board

Backer board was installed before tiling began.








tile B4 grout

Placing tile. It was finished with a light brown grout.




Tiling was actually fun because we were on the home stretch and it brought such warmth and a personal touch. The cats couldn’t care less, but we love the tile. We added a soft brown grout between tiles.


Finishing touches: A large log (found near a river bank) was also added, as well as final bits of woodwork and paint. Scatching post, litter box, water bowl, lantern, grass for grazing, and cushions for comfort (with washable covers) were the final touches to our Casbah Catio.

The Casbah Catio

Swirlee & Luna enjoying their Casbah Catio. We later wrapped portions of the log with sisal rope to entice climbers, but so far it’s only been used for scratching.


© 2017 Eileen M. Stark

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8 thoughts on Catios Keep Cats and Birds Safe

  1. Beautiful! Can I hire your husband! Great choices on the roof and floor. Might steal some ideas from you.

    1. Thank you! And thanks for the link to my site. All the best with your catio-building business!

  2. We built a catio onto the outside of my sons conservatory, it’s amazing, it has a tunnel through the wall to outside, perfect apart from winter as at the coldest we plugged in an oil filled electric heater, big mistake as cost a fortune, any ideas for warmth would be good and any idea how cold can cats cope with. Perfect for summer as they go out through tunnel and lie in the shade of the garden catio.

    1. Liz, I wouldn’t recommend trying to heat a catio … unless you really want to increase your carbon footprint! Situating it where it can get some winter sun is best, but not always possible, and of course yours is completed so you can’t change that. Cats’ tolerance of cold varies a bit. One of ours (a young male) goes out into the catio when it’s in the 30s for maybe 5 minutes, while the others last about 2 seconds. They definitely prefer temps above 60ºF.

  3. I’m getting ready to move into my first home.. I’m very blessed as my family is paying for most of the interior renos!!.. however I do have a family of 5 cats.. they turned 2 on 3/28/20.. and I love each one!.. anyway my new home is considered a historic home so I’m praying that the city won’t care if I build an inexpensive but as large as possible, catio. One where they can go in and out on their own. Maybe you have some suggestions? As I need to build a large one, but I’m on a budget.. I’d also like to have a door on the outside enclosure so I can go in & out and be able to clean their boxes, etc… maybe even be able to sit inside with them!!.. that’s my dream!! I love the example enclosure ideas as well..(btw: it’s a small Spanish style home.
    I truly appreciate all of your information and your suggestions!
    Thanks again
    -Andrea Goodrich

    1. I think it’s quite common for catios to have an external door (unlike ours that has one that opens to our house). I know of someone who built one with an external door, bench, etc.; she also hung some pretty vintage stained glass windows in it. I suggest using reclaimed materials as much as possible; it should keep costs down as well. I would think that if you keep it fairly small the city won’t care … (or try to keep it hidden in the back of the house but where the cats can see some greenery, birds, etc). The FCCO in Portland has a lot more info: They also have a video of their 2022 Catio Tour (click on Catio Tour Tickets). Good luck, Andrea!


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