As pet lovers, we can’t ignore the plight of outdoor and feral cats, especially during the harsh winter months. When temperatures drop, these resilient animals face freezing conditions with little protection. That’s why we decided to make a warm, insulated shelter using materials we already had on hand. Not only is this a budget-friendly solution, but it also provides a safe haven for cats in need. Below, we’ll walk you through how we built our DIY cat shelter step by step—so you can create one, too!

❄️🐾 No cat should freeze this winter! 🐾❄️

An effective winter cat shelter can be made for $15 or less, and might even be possible with supplies you already have lying around your house.

Sections:

• How Cold is Too Cold
• Supplies You Could Use
• How We Made A Shelter With Materials We Already Had
• Tips for Making Your Own Shelter
• Other Examples of DIY Cat Shelters
• Where Can I Learn More?

How Cold is Too Cold

45°F and above: Typically safe, but consider your pet’s breed, age, and coat thickness to ensure comfort.

32°F to 44°F: Pets sensitive to the cold may feel uneasy, though most dogs can still enjoy walks suited to their size, age, and coat.

20°F to 31°F: Small breeds, pets with thin or short coats, and those with weakened immune systems are more vulnerable. Keep outdoor time brief and monitor for signs of discomfort.

Below 19°F: All pets face risks of frostbite and hypothermia. Avoid leaving them outside and minimize outdoor exposure as much as possible.

Anytime the temperature drops to “freezing”, or generally requires covering pipes, dripping faucets, or covering plants, it’s a fair assumption that outdoor animals will also need shelter from the cold.

Supplies You Could Use

The shelter itself:

• Styrofoam bins, such as used to ship perishable food and medical supplies.
• Plastic storage bins with removable lids, such as Rubbermaid™ bins.

Something to cut an entrance to the shelter & extra ventilation holes

• E.g., box cutters, dremmel, scissors, jab saw, drill

Something to secure a roof/life on the shelter

• E.g., glue, duct tape

Something for extra insulation, bedding, or padding

• E.g., straw, packing peanuts, batting, poly fill, scrap fabric, shredded newspaper

Something to elevate the shelter off the ground and secure it in place

• E.g., 2x4s underneath the shelter & a brick on ontop

 

How We Made A Shelter With Materials We Already Had

Watch The Process In Action:

Materials & Tools You’ll Need:

Supplies:

• Styrofoam Cooler – We had one on hand, but you can find affordable options at Walmart for around $5.
• Duct Tape – For securing insulation and sealing the shelter.
• Insulation (Optional) – We used poly insulation for added warmth.
• Plastic Bags – Used to keep the insulation dry and prevent mold.
• Scrap Fabric – Perfect for creating a doorway flap that helps retain heat.

Tools:

• Box Cutter – For cutting the entrance hole.
• Sharpie – To mark cutting lines.
• Adhesive (Optional) – Ensure it’s safe for use with Styrofoam.

How to Build the Shelter

Step 1: Create the Entrance

A cat only needs a small opening to enter—about 5.5 to 6 inches in diameter, or roughly the width of their whiskers. A small entrance helps in several ways:
✅ Prevents larger animals, like raccoons, from entering.
✅ Retains more heat inside the shelter.
✅ Reduces wind drafts for better insulation.

To create the entrance:

1. Mark a hole on one of the short sides of the cooler using a Sharpie.
2. Carefully cut along your markings with a box cutter.
3. Remove loose Styrofoam debris and ensure the opening is smooth.

Pro Tip: If adding a second escape door, avoid placing it directly across from the main entrance, as this could create a draft.

Step 2: Add Drainage Holes

Even with insulation, moisture can build up inside the shelter. To prevent water accumulation:

• Flip the cooler over and poke small drainage holes into the lowest part of the shelter.
• This will allow any water or condensation to escape, keeping the shelter dry and comfortable.

Step 3: Add Insulation or Bedding

For extra warmth, we created DIY insulation packs:

• We stuffed batting into gallon-sized plastic bags, then squeezed out excess air before sealing them.
• The bags were then covered in duct tape to prevent punctures.
• If using these packs as insulation (rather than bedding), secure them to the walls and floor of the shelter with tape.

If you prefer bedding instead of insulation, straw is the best option—it repels moisture and keeps the shelter warm. Avoid blankets or towels, as they retain moisture and can freeze in cold weather.

Step 4: Make a Door Flap

To help keep warmth inside, we made a simple door flap using scrap fabric:

• Cut a fabric piece slightly larger than the entrance.
• Secure the top of the fabric over the opening using strong tape or adhesive.
• The flap will allow cats to enter while blocking cold air from rushing in.

Step 5: Secure the Lid

To ensure the shelter remains intact through winter:

1. Apply adhesive along the edges of the cooler lid in a well-ventilated area.
2. Firmly press the lid onto the base and hold for a few seconds.
3. Use duct tape around the edges to create a strong seal.
4. Be careful not to cover the drainage holes.

Step 6: Placing the Shelter: Where and How to Set It Up

Once your shelter is complete, it’s important to position it correctly to maximize warmth and safety.

Best Placement Tips:

✔ Pick a sheltered area – Look for a spot where cats naturally hang out, like under porches, near fences, or against buildings.
✔ Face the entrance away from the wind – This prevents cold drafts from entering.
✔ Elevate it off the ground – Rain and snow can seep inside, so place the shelter on wood planks, bricks, or lawn mower ramps to keep it dry.
✔ Weigh it down – Styrofoam shelters are lightweight and can be blown over easily. Place a heavy object, like a rock or brick, on top to keep it stable.

Encouraging Cats to Use the Shelter

To help feral cats find and trust their new winter home:
🐾 Place treats or food along their usual path leading into the shelter.
🐾 Sprinkle catnip inside to make it more inviting.
🐾 Avoid checking on it too often—feral cats may be wary of human scent.

Tips for Making Your Own Shelter

 Choose the Right Location

• Place the shelter in a quiet, safe, and hidden spot, away from heavy foot traffic or predators.
• Position it on a slightly elevated surface to prevent flooding.
• Ensure the opening faces away from prevailing winds for added warmth and protection.

Use Durable & Weatherproof Materials

• Pre-made options: Repurpose storage bins, coolers, or sturdy wooden boxes. Look for weatherproof materials to withstand rain and snow.
• DIY shelters: Use plastic tubs or Rubbermaid containers, as they’re easy to cut and insulate.

Insulate for Warmth

• Line the interior walls with foam board or Mylar blankets to retain heat.
• Add straw for bedding—it’s insulating and stays dry. Avoid blankets or towels, as they can absorb moisture and freeze.

Make the Entrance Cat-Friendly

• Cut a small opening, about 6-8 inches wide, to allow cats to enter while keeping larger predators out.
• Install a flap or plastic covering over the entrance to block wind and rain.

Keep It Off the Ground

• Raise the shelter a few inches off the ground using bricks, pallets, or wood to prevent heat loss and water damage.

Waterproof & Secure the Shelter

• Use duct tape, silicone caulk, or weatherproof sealant to seal any cracks or gaps.
• Add a tarp or plastic sheet over the shelter for extra waterproofing.

Provide Food & Water

• Place food and water near the shelter but not inside, to avoid attracting other animals.
• Use heated bowls or add a pinch of sugar to water to delay freezing.

Maintain the Shelter

• Check the shelter regularly for wear and tear, accumulated snow, or any displaced bedding.
• Ensure the shelter stays dry and clean throughout the winter.

Group Shelters for Extra Warmth

• If caring for multiple cats, place two or more shelters near each other (but not sharing walls) so cats can huddle together for warmth.

Bonus Tip:

• Consider using non-toxic straw or hay for insulation, as they provide excellent warmth without becoming damp.
• Creating an outdoor shelter is a compassionate way to help feral and stray cats survive harsh winters. A little effort can make a big difference in their comfort and safety!

Other Examples of DIY Cat Shelters

This blog uses a 20-gallon rubber storage container, gorilla tape, and pine straw. It includes stepwise instructions and pictures for each step.

This blog uses a $5 Walmart styrofoam cooler, duct tape, plastic bags, and old towel. It includes detailed stepwise instructions and pictures for each step.

This blog uses a plastic storage tote, bubble insulation, gorilla tape, and straw. It includes simple stepwise instructions, but doesn’t have pictures at each step.

This blog uses two plastic tubs (30 & 20 gallon), box cutter, straw, and styrofoam. It includes stepwise instructions, pictures for each step, and a video showing how to make the shelter.

This blog uses a Styrofoam cooler, two rubber containers, straw, and a box cutter. It includes instructions and pictures.

Final Thoughts

Building a winter shelter for feral cats is a simple yet powerful act of kindness. By repurposing materials you already have, you can provide warmth and safety for cats who have nowhere else to go. Whether you’re a dedicated animal rescuer or just someone who wants to help, taking the time to create a shelter can make a world of difference for these resilient animals.

Where Can I Learn More?

If you’d like to schedule an appointment or discuss any concerns for your pet, please call or text us at (843) 966-3362. If you’re a current client, you can also schedule an appointment online.

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