My dogs dig holes in my flower beds like it’s their job. Last spring, one of them, Biscuit, uncovered a nest of kittens under my porch instead.
Their mother was a stray who’d been sleeping under there for weeks without me noticing. That was the week I finally built her a proper shelter.
A cardboard box under a porch isn’t a real plan for a North Carolina winter.
If you’re here, you probably have your own version of that story. Maybe it’s a cat who showed up on your porch. Maybe it’s a colony you’ve been feeding for a while.
Either way, a DIY outdoor cat house is one of the most useful things you can build in an afternoon. You likely already own half the materials.
This guide walks through the easiest build first, a two-tote shelter that costs less than a nice dinner out. Then it covers a sturdier wood option for anyone who wants something built to last for years.
Along the way, I’ll cover sizing, insulation, and where to actually put the thing once it’s done.
Why Build Your Own Outdoor Cat House
A store-bought outdoor cat shelter runs anywhere from $60 to $140, based on the models I found while researching this. A homemade one made from totes usually costs $20 to $35.
A basic wooden version runs from $45 to $80, depending on what you already have in the garage.
The bigger reason to build one yourself is control. You decide the exact size, the placement of the entrance, and how much insulation goes in the walls.
You can also build it to match the exact cat, or cats, you’re sheltering. No more guessing at a size on a shelf.
Either build here protects a cat from wind, rain, and cold. That matters more than people realize. Cats can’t regulate their body heat the way we can, and a wet, unprotected cat loses heat quickly.
Getting the Size Right First
A cat house should be just big enough for a cat to turn around and stretch out.
Bigger is not better here. A larger box takes more body heat to warm up, so an oversized shelter can actually leave a cat colder.
Aim for a 6-inch-wide entrance, roughly 6 inches tall. That’s wide enough for a cat to pass through easily, but narrow enough to keep out raccoons.
If you’re sheltering more than one cat, add a second entrance on the opposite side. It gives a cat a way out if something threatening shows up at the first door.
For a single adult cat, aim for about 18 by 20 inches inside, with 16 to 18 inches of height. For two or three cats sharing a space, size up to roughly 24 by 24 inches.
Materials and Tools for the Tote Shelter
This build uses common materials, most of which you can find at a hardware store or already have at home.
Materials:
- One large plastic tote with lid (around 30 gallons)
- One smaller plastic tote with lid (around 18 to 20 gallons)
- A thin sheet of rigid foam insulation, or a roll of straw
- Duct tape
- A bag of straw for bedding (not hay)
Tools:
- A box cutter or fine-toothed saw
- A permanent marker
- A hair dryer (it softens plastic before cutting)
A quick note on straw versus hay: straw repels moisture and stays dry, while hay absorbs moisture and can grow mold.
How to Build a DIY Outdoor Cat House Using a Tote
Step 1: Mark the Entrance
Set the smaller tote next to the larger one and trace a 6-inch circle on one of the short sides, near the bottom edge. Keep it low to the ground so the cat doesn’t have to step up to get inside.
A jar lid or round cookie cutter makes a clean template.
Step 2: Soften the Plastic
Run a hair dryer over the marked circle for about two minutes before you cut.
Warm plastic cuts cleanly and evenly. Cold plastic tends to crack or splinter at the edges, making it harder to seal the entrance later on.
Step 3: Cut the Entrance
Use a box cutter or fine-toothed saw to cut along your traced circle.
Go slowly and apply steady pressure. Keep your fingers well clear of the blade. Once cut, run your finger around the edge to check for any sharp or jagged spots you missed.
Step 4: Repeat on the Small Tote
Place the smaller tote inside the larger one and line up where the doorway needs to be. Mark the matching circle and cut it the same way.
Both entrances must align so a cat can walk straight through without turning sideways.
Step 5: Add a Base Layer of Insulation
Before you lower the small tote in, set a thin sheet of rigid foam board or a firm, packed layer of straw in the bottom of the large tote.
This base layer stops the ground from pulling heat out through the floor.
Step 6: Fit the Small Tote Inside the Large One
Lower the small tote into the large one and line up both entrances.
Press down until it sits flat on the base insulation layer. The gap between the two tote walls is where your main insulation goes in the next step.
Step 7: Pack Insulation Between the Walls
Fill the gap between the two totes with straw or cut foam scraps.
Pack it firmly and pay extra attention around the entrance hole, where cold air enters fastest. A well-stuffed wall gap makes a big difference on freezing nights.
Step 8: Fill the Inner Tote With Straw
Add a thick layer of straw inside the smaller tote.
This is where the cat actually sleeps, so be generous. Straw holds body heat well overnight. Replace it every few weeks in winter, since flattened straw stops working quickly and the shelter cools down fast.
Step 9: Seal the Edges
Run duct tape around every sharp or jagged edge near the entrance on both totes.
A cat brushes against that opening every time it comes and goes. Rough plastic edges can cut paws or snag fur, so take a few extra minutes here.
Step 10: Snap the Lids On
Press both lids down firmly until they snap closed and sit flush.
A lid that gaps or lifts lets rain and wind in. Your shelter is ready to be placed outside. Set it on bricks or a pallet to keep it off the ground.
Want Something Sturdier? Try the Wood-Frame Option
If totes feel too flimsy, or you want a shelter that lasts several winters, try the wood-frame house instead. It follows the same double-wall idea, just built from lumber and plywood instead of plastic bins.
Extra materials you’ll need:
- 2×2 lumber for the frame
- 3/4-inch plywood for the floor and walls
- 1/4-inch plywood for interior wall panels
- Rigid foam insulation or fiberglass insulation
- Asphalt shingles or roofing felt for the roof
- Wood screws and wood glue
Basic steps:
- Build a simple floor frame out of 2×2 lumber, then attach a plywood floor panel on top.
- Frame the four walls with 2×2 lumber, and attach exterior plywood panels to each one.
- Cut a 6-inch entrance into the front wall, and sand the edges smooth.
- Slide rigid foam insulation between the exterior walls and a second, interior layer of thin plywood.
- Build simple angled rafters for the roof, and cover them with plywood, then roofing felt, then shingles.
- Raise the finished house on bricks or a low pallet so it sits a few inches above the ground.
This build takes longer, usually a full day, and calls for a saw, drill, and some basic woodworking know-how. But it holds up to weather far better than plastic over the long run.
Insulation, Weatherproofing, and Where to Put It
Foam board insulation holds heat well and cuts easily to fit tight spaces. Straw does something similar, and it also gives a cat something soft to burrow into.
Both work. Skip fabric, blankets, and towels as insulation, since they soak up moisture and can freeze solid on cold nights.
Where you place the shelter matters almost as much as how you build it. Set it somewhere out of direct wind, ideally against a wall, fence, or under a porch roof.
Raise it a few inches off the ground with bricks or a pallet. Ground moisture pulls heat out fast.
In summer, the same shelter needs a little airflow. Prop the lid slightly, or drill a couple of small holes near the top for airflow. This keeps the inside from overheating.
If you’re sheltering feral or community cats, place the house somewhere quiet and hidden from foot traffic. Cats that aren’t used to people feel safer tucked behind a shed than out in the open.
Putting It All Together
That kitten nest under my porch turned into three cats who still show up most evenings for dinner. This DIY outdoor cat house has held up through two winters now.
It didn’t take fancy tools or a big budget, just an afternoon and a couple of plastic totes.
If you take one thing from this guide, let it be this: keep the entrance small, keep the insulation dry. Everything else, you can adjust as you go.
Get it up off the ground, too. That one detail matters more than people expect. Build the tote version this weekend, or work up to the wood-frame one later.
Either way, you’ll have given a cat somewhere warm and dry to ride out the weather.
Frequently Asked Questions
How Big Should the Entrance Hole Be?
Aim for about 6 inches wide and 6 inches tall. That size lets a cat move through easily while keeping out raccoons and other larger animals. For multi-cat shelters, add a second entrance on the opposite side as a backup exit.
Should I Use Hay or Straw for Bedding?
Always use straw, not hay. Straw is hollow and repels moisture, so it stays dry and insulating through wet weather. Hay absorbs water and attracts mold, which makes the shelter damp and cold rather than warm.
How Many Cats Can a Shelter Comfortably Hold?
A single-cat shelter works best with an interior size of about 18 by 20 inches. For two or three cats, size up to about 24 by 24 inches, and add a second entrance. Cramming too many cats into one small space reduces comfort, even if it helps with warmth.
