Keeping cool cats warm
Winter shelter is essential for feral and stray cats living in frigid climates and can help them thrive despite low temperatures. What you'll find on this page are examples of inexpensive, do-it-yourself shelters that can be built in a matter of hours or less, as well as one high quality vendor who sells and ships pre-fabricated shelters. You'll even find how in a pinch you can build an emergency shelter out of cardboard boxes.
A good cat winter shelter is going to (1) be made of material that provides good insulation, (2) have minimal empty air space when all the cats using it are inside, and (3) be waterproof. What happens is when the cats are in the shelter, they give off body heat which the shelter traps, creating warmth. If the shelter is not made of good insulation, the heat will pass through the walls. If there is too much empty space, the cat or cats using the shelter won't be able to generate enough heat. And of course you need the shelter to be waterproof so the interior stays dry.
Further down this page, you'll find info on placement of shelters, insulating materials to place inside your cat cabins, extra protection for extreme cold, and installing flap doors. For more on winter care, see how to stop freezing water.
Neighborhood Cats Winter Shelter
If you have access to a table saw, you can turn a hard Styrofoam sheet normally used for insulating walls into a great winter shelter that can comfortably house three or four cats. A single sheet (8 ft L x 2 ft W x 2 in thick) is cut up into pieces which are then joined together used silicone glue. Before putting the top on, linoleum tiles are added to the floor. A coat of deck paint for camouflage and protection finishes the job. Download our instructions for a step-by-step guide.
Storage Bin
Turn a durable storage bin like the Rubbermaid Roughneck Tote into a warm winter hideaway. The interior walls, floor and ceiling are lined with pieces of 1 inch thick hard Styrofoam cut from an 8 ft L x 2 ft W sheet. Precise edges are not necessary so the pieces can be hand cut using a ruler and box cutter. Straw is stuffed in the bottom and a doorway cut open in the side. Like most winter shelters, this one is lightweight and should be weighed down with a board or, our favorite, one or two concrete bricks. Follow these instructions to assemble. A tote approximately 30 gallons will house a few cats while a 55 gallon bin will hold two or three more. (Photo by Carole Milker).
Feralvilla (for purchase)
The company Feralvilla manufactures an excellent cat winter shelter made of wood composite. It's pre-primed for painting, comes with a fully shingled roof and can be assembled with a screwdriver in 15-30 minutes. There are two levels inside the shelter - cats enter the lower level from outside, then climb up through an inner opening to the fully insulated upper floor. The wood composite is environmentally friendly and uses a low toxicity resin to bind the fibers.
Styrofoam shipping boxes
Perishable items like meat and fish are often shipped in Styrofoam boxes such as Omaha steaks. Boxes can also be found at supermarkets, fish stores, butcher shops and even veterinary clinics because vaccines are shipped in them. Or you can buy a 45 quart cooler from Walmart or other distributor. These well insulated crates can be easily transformed into feral cat winter shelters for one or two cats (unless you find a large box which could house more felines). To convert the box into a shelter:
(1) Using a utility knife or box cutter, open a doorway in one of the short sides of the box, approximately 6 inches by 6 inches. Keep the bottom of the doorway a few inches above ground level, to prevent flooding in the event of rain.
(2) Permanently attach the top cover to the main body of the box with silicone glue. The silicone will seal the lid and make the shelter waterproof.
(3) To camouflage and further protect the shelter, apply a coat of an appropriately colored deck paint.
Other do-it-yourself designs
Feral cat caretakers are an inventive lot and there are many other designs for winter shelters that make use of Styrofoam and durable storage bins, and are waterproof, well insulated and have minimal empty space. The level of skill with construction and the need for power tools varies among them. Here's some that caught our eye:
Storage bin with a flower pot entryway by Bushwick Street Cats (photo)
One storage bin stacked inside another by Spay and Stay (Note: we recommend not using clear transparent bins)
Storage bin with a windbreak interior panel by John V.
Emergency Shelter
When a bad storm or sudden cold snap is arriving soon and time is of the essence, use the design described here to quickly build an adequate temporary shelter. You'll need a cardboard box, duct tape, shredded newspaper, a pair of scissors and either a plastic drop cloth that's 3 millimeters thick (a common item in the paint department at Home Depot or a hardware store) or contractor trash bags at least 3 millimeters thick. To assemble:
(1) Take the cardboard box (cardboard is actually good insulation) and tape all the seams shut with duct tape.
(2) Wrap the box completely with the drop cloth or trash bags, cutting the plastic as necessary and making as few seams as possible. Secure onto the box with duct tape, liberally and tightly wrapping the tape around the sides of the box and sealing any seams in the plastic. This will make the shelter waterproof.
(3) Cut a doorway in one of the shorter sides of the box approximately 6 inches by 6 inches, leaving the bottom of the doorway a few inches above the bottom of the box to prevent flooding. Use duct tape to secure the loose plastic around the opening onto the cardboard.
(4) Place shredded newspaper inside the box, filling it up to the bottom of the doorway in front and a little higher towards the back. The cats will gain added warmth by burrowing into the newspaper.
For added insulation, start by placing a slightly smaller cardboard box inside a larger one and fill the gap between them with rolled-up newspaper. Then proceed with steps 1 through 4, above, being sure to cut the doorway through both boxes.
Placement
Put the shelters in a familiar location where the cats are already used to spending time. Placing them near where the cats are fed has the advantage of limiting how far they'll have to travel to eat during inclimate weather. Don't put the shelters out in the open, like in the middle of a yard or lot, but under or against something, like a wall, fence, tree, porch or some type of overhang. Ideally, the spot will be out of the wind but still exposed to the sun. Encourage your cats to start using the shelters by sprinkling catnip at the entrances.
To prevent flooding, raise the shelters off the ground by placing them on pallets, bricks or similar, but make sure they're stable and not wobbly. Most shelters, especially if made of Styrofoam, will be lightweight so weigh them down by placing one or more heavy objects on top, like concrete bricks, but don't put too much weight on and damage the roof.
If you have more than one shelter, position two of them so the doorways are facing each other a short distance apart. Place a board on top of the shelters to cover the space between them (see photo). Having the shelters face each other will help break the wind and the board spanning the gap between them will protect against rain and snow, plus create a little clear area where you can put food and water if necessary.
If the surfaces of the shelters are paintable, camouflage them with paint a color that will blend in with their surroundings. Grey, green and reddish-brown are often most useful. For the best protection, use an exterior latex deck paint.
Interior insulating materials
For extra warmth inside the shelters, you can add materials the cats are able to burrow into and surround themselves with. Straw is best because it's loose, dry and good insulation. Don't confuse straw with hay, which is moist, can get moldy and cause health issues, and should never be used as bedding. Shredded newspaper will work if you can't find straw. Avoid the common mistake of placing a towel, blanket or folded newspaper flat on the shelter floor. Because a cat typically lies on top of these items and doesn't go under them, they will draw body heat out and make the cat colder, not warmer.
Straw can be ordered from Home Depot which ships by the bale. For smaller amounts (a bale is big!), buy a 4 lb. box from Kitty Tube (photo) or check out a craft store like Michael's for small decorative bales. Horse stables and nurseries sometimes have straw for sale or know where you can get some. Another option is look for businesses that use straw in their autumn displays. Instead of throwing it away after Thanksgiving, perhaps they'll donate it to you!
An exception to the "nothing flat on the floor" rule is a self-warming pet pad made of materials which absorb and retain a cat's body heat, like the Carolina Pet Company Purr Padd. You can also microwave a Snuggle Safe Microwave Heat Pad, place it in its cloth cover and tuck it inside the shelter. (Snuggle Safe pads can also be used to stop water from freezing.)
Extreme cold (Mylar blankets)
In regions where extreme cold is often the norm during the winter, shelters can be made warmer by lining the interior with Mylar blankets. Mylar is a thin polyester material that traps and reflects body heat back to its source. You'll often find a Mylar blanket in winter survival kits. When assembling your shelter, before you attach the roof, cut a Mylar blanket into pieces and glue them onto the inside walls, floor and roof. Use a non-toxic glue, such as Weldbond. Tuck in or cut away any loose material at the seams so the cats won't be tempted to pull or chew at it.
Flap doors
In our experience, well-made cat winter shelters do the job without a flap over the doorway. That said, putting a cover over the doorway can help keep cold air out and warm air in. A thick piece of vinyl or rubber mat, like a floor mat, will work. The material has to be waterproof and thick enough to provide some insulation but light enough for the cats to easily pull it open.
Use extreme weather VELCRO, strong glue or plastic nuts and bolts to attach the flap. For the nuts bolts, drill two holes the diameter of the bolts through the top of the flap and two corresponding holes above the doorway. Then, going from the inside of the shelter outwards, insert the bolts then tighten the nuts. Unless they're already short, you want the bottom of the bolts facing out so they're not protruding inside the shelter and risking harm to a cat. You can use a hacksaw to cut down on any unneeded bolt length.
Wait to attach a flap door until after the cats are already using the shelter. Otherwise, it might deter them from going in and exploring. Once they've decided that's their house, they'll figure out how to pull the flap back and go in.
Do you need two doors?
Usually, no. Two doors creates the possibility of drafts and can defeat the shelter's purpose of providing warmth. The only time two entrances might be needed is in an area where the cats have predators like coyotes who are frequently present. The idea is that if a coyote pokes his nose in the shelter, the cats will have time to run out the other door. In most situations though, the possibility of a predator trapping a cat is remote and not worth making the shelter less functional.