Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How to Build an Insulated DIY Outdoor Cat House: Step-By-Step Guide

Share

four outdoor cat shelters

Outdoor cat shelters are fabulous for indoor cats who occasionally spend time outside. It’s also great for feral cats, abandoned cats, and any other cats who might need a place to stay—even if it’s your neighbor’s cat that just needs a nap.

Have you thought about making an outdoor shelter, but you’re not sure where to start? We have you covered! This is an incredible design that is easy to follow and relatively simple to make—although we recommend reviewing materials and tools to see if you’re comfortable with the skillset.

So, without further ado, let’s get cracking on this DIY!

divider cat paws oct 2024

Reasons to Build a DIY Outdoor Cat Shelter

Building an outdoor cat shelter will cost significantly less than buying a cat house from a store. So, the very first upside is money saving, for sure! If you’re paying to feed and shelter homeless kitties, it can take a toll on your bank account, so cut corners when you can by building your own shelter.

You can also make your DIY cat house however you want. You don’t have to buy a prefabricated model that might be cheaper and quicker to fall apart.

A Little About the DIY

This project is a very standard cat shelter, and you likely have a few of the supplies already on hand! It’s estimated that creators will spend an average of $45 to build. So, always ensure it’s in your budget and cut corners when possible.

Supply List
  • 30-gallon plastic tote + lid
  • 18-gallon plastic tote + lid
  • 1 roll of fiberglass insulation or styrofoam
  • Or 1 sheet of rigid 1-inch foam board/polystyrene
  • Duct tape
  • A bottle of expanding foam
  • Fine toothed saw

Considerations

Thick plastic is extremely hard to cut, so make sure you are careful and use the right tools. Typically, a fine-toothed saw works best for the job. If you use anything else, you could make the job a lot harder or even get injured in the process.

divider 2 cats

How to Build an Insulated DIY Outdoor Cat House

Now that you have your supplies and are ready to build, let’s get cracking.

1. Cut the doorway for the shelter in the center of the box using a saw.

Make the opening big enough that cats can go in and out without issue. Many totes have different curvatures in them also, so make sure you aren’t doing extra work for yourself.

a fine toothed hacksaw
Image Credit: Anelo, Shutterstock

2. Grab your duct tape.

Carefully seal the edges of the opening to cover jagged areas. Plastic can be very hard and pokey if it’s cut, so it’s just a safety precaution to protect your pet.


3. Next up, insulation.

In order to put the second box inside, you will need to line your largest tote with insulation. Your fiberglass insulation will be a certain thickness. Generally, rolls range from 3 to 6 inches. In this case, you won’t want to make the insulation too thick, as it will make it more difficult for the totes to fit together properly. We recommend 3 inches.

Put a piece of insulation in the bottom of the larger tote. This way, it provides the appropriate height to measure where to cut the smaller tote. Then line the sides with insulation. You will want your totes to align so the entrance isn’t askew.

layers of Pink fiberglass insulation
Image Credit: Cavan Images, Shutterstock

4. Cut the hole for the smaller tote.

After the installation is installed, you’ll place the smaller tote inside of the larger tote, so make sure the two align correctly. Measure the correct distance up from the bottom and sides.

Then, take the smaller tote out and cut out the entrance using the saw.


5. Duct tape the opening of the smaller tote.

You will repeat this step the same way you did the larger tote. The opening needs to be of like size for the design to work properly.

duct tape
Image Credit: Pixabay

6. Align the totes.

Place the smaller tote inside the other and try to line up the doorway as best as you can.


7. Fill in with insulation.

Make sure there are no gaps to avoid chilly spots. It can make all the difference. You don’t have to be a fancy cutter, either; you can cut pieces to fit as needed. You can also use expanding foam. This product will fill in all the gaps to ensure an insulted seal. This is especially necessary around the entrance.

Gray cat looks from its wooden house
Image Credit: ovbelov, Shutterstock

8. Make sure all the insulation is in the box.

Cut the piece or tuck it in if you see any peeking out. Ideally, you could create one main cut and wind it around to the doorway. Then, you could simply place a piece of insulation above and below the door.


9. Place the lid on tightly.

The lid for the larger tote should fit comfortably right on top.

And voila! There you have it! You have your very own insulated cat box to house all the neighborhood vagabonds so they can stay safe. Or, perhaps you have an outside cat that needs the extra warmth, and now you have built them their very own cozy cabin in the winter wilderness.

Either way—the kitties will certainly appreciate it through the colder months. It will help prevent frostbite, hypothermia, and all sorts of other potential complications due to cold weather.

cat on snow
Image Credit: melnikof, Shutterstock

If you want a more in-depth guide on creating this insulated outdoor cat house, alleycatadvocates.org has a similar plan on their site. Alternatively, you can check out our top picks for a DIY outdoor cat house in the post below:

divider cat paws oct 2024

Final Thoughts

What did you think of these instructions? Did you find it simple enough? I certainly hope it wasn’t too much trouble. Remember that you can adjust to better suit your needs. Once you get the hang of it, you can create a more advanced version or keep it simple.

Plus, this warming box is wonderful for multi-cat use. So, you could even make a few and house your local cat colony throughout the chilly months. These boxes are well-insulated, cheap to make, and perfectly cozy for our outdoor feline friends.


Featured Image Credit: okanakgul, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

2 Responses

  1. do I need to do anything different to be able to put a heating pad in one of these? our cat likes to use his house as a scratching post and has completely destroyed two but we still have the heating pads. he lives on our porch very cold in the winter time and hopind a plastic tote will keep him from destroying it this winter as they are expansive and moneys tight this year due to the government shut down.

    1. Hi Vanessa, if needed, including an outdoor-rated, thermostatically controlled pet heating pad in the DIY insulated cat house design is both safe and highly recommended for providing essential warmth in cold weather. The house's construction using plastic totes and rigid foam or fiberglass insulation is completely compatible with these specialized heating pads because the pads are designed to heat only to a safe, regulated temperature (around the cat's normal body temperature of 102 degrees Fahrenheit), which is not high enough to melt the plastic or insulation materials. Safety relies on using a dedicated, outdoor-grade pet pad with a chew-resistant cord, routing the cord securely away from the cat, and plugging it into a weatherproof, GFCI-protected outlet.

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Catster's Digital Magazine is Back!

Vet-approved health & behavior advice

Real cat stories & community features

Chatting About the Rainbow Bridge, Euthanasia, and Laughter During Grief | Chatty Cattys, Episode 24

If you’ve ever felt the loss of a beloved cat, or are dreading the day when your pet crosses the rainbow bridge, you’ll...

The Simple Reasons Cats Refuse to Let Anyone Use the Bathroom Alone

Cats have an extraordinary talent for making themselves present in the most inconvenient places, and the bathroom ranks near the top of the...

A Paw-sitive Milestone: Canada Officially Becomes a Declaw-Free Nation

Canada has officially become a declaw-free nation. On May 25, 2026, a new regulation was filed in Ontario under the Provincial Animal Welfare...

The Surprisingly Simple Ways to Help a Cat With Hairballs

Cats spend an astonishing amount of time grooming. It is part hygiene routine, part comfort ritual, and part instinct that traces back generations....

More related

How to Keep Cats Away From Poinsettias: 7 Vet-Verified Ways

With the holidays comes decorating, whether hanging up pretty baubles or keeping a few lovely holiday plants around. But as a cat owner,...

10 Best Tasting Cat Foods for Picky Cats in 2026 – Reviews & Top Picks

It’s no secret that our cats love dinnertime. It’s arguably their favorite part of the day! But some cats are a little on...

Gum Disease in Cats: Our Vet Explains Causes, Signs & Treatments

No one enjoys being woken up in the morning by a kitty crying for breakfast and attention, but the routine is even less...

Can Cats Eat Slim Jims? Vet-Approved Nutritional Science & Alternatives

Because your cat is a carnivore, you might be wondering if your furry friend can eat Slim Jims. Although Slim Jims are likely...

Keep reading

How Many Muscles Does a Cat Have in Each Ear? Vet-Reviewed Anatomy (With Infographic)

When it comes to dogs, we all know how good their senses are, especially for smelling and hearing. But in this regard, cats are similar to their canine counterparts and even have a few epic secrets of their own. A...

A man's hand scratches a fluffy cat behind the ear

Cat Bunting: What Is It? Vet Approved Feline Behavior Guide

Cats are curious creatures that have many behaviors that we must study to understand, as they are not natural human ones. One such behavior is something called cat bunting. In short, cat bunting is when a cat places or butts...

Girl butting heads with her ginger cat

Why Do Cats Bring You Their Toys? 8 Vet-Approved Reasons & FAQ

When you think of a pet bringing you toys to play with, you probably picture the wagging tail and doleful eyes of your dog. But many people don’t realize that cats often bring their owners their toys too. Not only...

two cats playing with a toy indoors

Why Do Cats Like Bathrooms? 10 Vet-Reviewed Reasons

Anyone who is a cat parent is familiar with their cat following them into the bathroom or making noise if the door is closed without them being let inside. So, why on earth do cats seem to love the bathroom?...

british shorthair cat peeps from the bathtub

Cat Regurgitation vs. Vomiting: Vet Reviewed Differences & How to Help

Owning a cat or several of them comes with a great deal of responsibility. Felines are independent creatures that can practically take care of themselves. However, if your cat gets sick or is involved in an accident, as a responsible...

Cat Regurgitation vs. Vomiting

Does Garlic Kill Fleas On Cats? Vet Reviewed Effectiveness Safety Explained

In addition to warding off vampires, garlic has multiple dietary and medicinal virtues. This bulbous plant can spice up the flavor of almost any dish while taking care of your cardiovascular health, protecting your liver, and combatting infectious diseases. However,...

Garlic

Why Do Cats Like Q Tips? 3 Possible Reasons & Vet-Reviewed Safety Tips

If you have ever noticed your cat chasing after strange objects and trying to chew on them, you probably understand how fun it is for cats to play around with Q tips. In your cat’s mind, Q tips are strangely...

Wooden cotton swabs and the paw of a gray cat on bright yellow background

How to Safely Burn Incense Around Cats: 3 Vet-Approved Tips

Incense is a plant material that gives off certain scents when burned, and it’s been around for centuries. People use it for multiple purposes, such as meditation, getting rid of negative energy, relaxation, and aromatherapy. Incense is deeply embedded within...

lighted incense stick

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.