Feral Cat Winter Shelter

The Neighborhood Cats Winter Shelter

For detailed instructions on how to build, click here
To view photos of how to assemble, click here. Picture trail courtesy of Arjun Ray.

Originally designed by Karin Hancock of Port Washington, NY, our favorite feral cat winter shelter has many advantages. The two-inch thick hard Styrofoam is excellent insulation and traps the cat's body heat, effectively turning the feline into a radiator.  Air space is purposely limited, so there is less volume to be heated. Typically, 3 to 4 cats can fit comfortably inside, although more might curl up on a severely cold night. 

The shelter is lightweight and should be weighed down.  Best is to place two shelters about a foot apart with the doors facing each other.  Bridge the gap by laying a piece of plywood across both roofs.  Now the shelters are fully protected against the elements.

After the cats have begun using the shelters, you might try adding a flap door which the cats can easily pull back.  A piece of a vinyl mat will do, attached by drilling (or poking) two holes above the door opening and using plastic nuts and bolts (like those used to attach toilet seats).  Never place water inside because it could spill and get the cats wet, threatening their health. 

Materials include an 8-foot sheet of hard Styrofoam (usually pink),  a few linoleum floor tiles, a tube of silicone sealant and deck paint.  Average cost will likely be in the range of $50 to $60 each.  Ideally the Styrofoam will be cut with a table saw in order to keep the edges of the pieces straight.

The CSM Stray Foundation Winter Shelter

Here's another idea inspired by the CSM Stray Foundation in Kew Gardens, Queens:

Materials needed are: a large Rubbermaid storage bin, an eight foot by two foot sheet of one-inch thick hard Styrofoam, a yardstick, a box cutter or utility knife, and straw, shredded newspaper or other insulating material. Then assemble as follows:

  1. Cut a doorway six inches by six inches in one of the long sides of the storage bin towards the corner. To prevent flooding, cut the opening so that the bottom of the doorway is several inches above the ground.
  2. Line the floor of the bin with a piece of Styrofoam, using the yardstick and box cutter to cut out the piece.
  3. In similar fashion, line each of the four interior walls of the bin with a piece of the Styrofoam.  Perfect cuts are not necessary. Don't make the Styrofoam go all the way up to the top of the bin, but leave a uniform gap of at least three inches between the top of these Styrofoam "wall pieces" and the upper lip of the bin. There needs to be room for an interior Styrofoam "roof" to fit.
  4. Cut out a doorway in the Styrofoam where it is lined up with the doorway that has been cut out already in the storage bin. Trace the outline of the doorway on the Styrofoam first before cutting.
  5. Stuff the bottom of the bin with straw or other insulating material to hold the Styrofoam interior wall pieces in place.
  6. Cut out a Styrofoam "roof" to rest on top of the Styrofoam interior wall pieces
  7. Cover the bin with its lid.
This shelter can be cleaned by taking off the lid and the Styrofoam roof. It's also lightweight and may need to be weighed down. A flap over the doorway is optional. Catnip can be sprinkled inside at first to attract the cats.


For $64.95 plus shipping & handling, the manufacturer FeralVilla will send you a pre-fabricated wooden insulated shelter that you can assemble with a screwdriver.  According to the website:

"The unique design has 2 levels -- a ‘labyrinth’-type lower level to keep out wind and water, and an insulated, upper level that allows the cat’s own body heat to be retained during cold weather.

"The overall size of The FeralVilla is 22" x 22" and about 21" high at the peak of the roof. The roof overhangs the main body by a couple inches to provide additional weather resistance.

"The basic construction materials are like those used in homes. All wood is painted to resist weathering and rot. The lower legs (that rest on the ground) are made from pressure treated lumber that is particularly resistant to rot and insect damage. Under normal outside conditions, the shelter is expected to last a minimum of 7 years."

Emergency Feral Cat Shelter!!

In an emergency, such as the aftermath of a bad storm or a sudden cold snap, you can quickly make an adequate temporary shelter out of a cardboard box, plastic sheeting (or trash bags), duct tape and shredded newspaper.  The cardboard provides some insulation, the plastic will keep the shelter dry and the newspaper will let the cats burrow in.

Take a cardboard box and tape all the seams shut with the duct tape.  Wrap plastic sheeting (a drop cloth 3 mm thick is best) or a heavy duty trash bag (3 mm thick contractor bags are best) around the box, securing it by liberally and tightly wrapping duct tape around the sides of the box.  Make as few seams as possible with the plastic and duct tape over any that are there.  In one of the shorter sides and a few inches above the ground, cut open a doorway about 6 inches by 6 inches.  It's important to leave a lip at the bottom of the doorway and not have the opening right on the ground.  Use duct tape to hold the loose plastic around the doorway in place.  Fill the interior up to the bottom of the doorway (and a little higher towards the back of the box) loosely with shredded newspaper.

Special tip!  Put a smaller cardboard box inside a slightly larger one for added insulation.

If possible, place the box shelter underneath something to protect it, like a tree or a porch, and on top of something to raise it off the ground, like a pallet.  Weigh it down with a couple of bricks or rocks, heavy enough to keep it in place but not to crush the top.  For permanent winter shelter, consider one of the alternatives below.

Other Alternatives

Spay and Stay of Lake County, Illinois, offers detailed plans and photos on its website for making inexpensive winter shelters from two Rubbermaid storage boxes: http://www.spayandstay.org/winter-shelter/

Another shelter created from Rubbermaid storage bins was designed by John V.; this version features an interior panel that serves as a windbreak. For complete DIY instructions click here

Animalkind of Hudson County, NY, provides photos and instructions on its website for converting Styrofoam packing containers into cold weather shelter: http://www.all-creatures.org/ak/feral-shelter.html

An adequate shelter for one cat can be made from a simple Styrofoam cooler available at any hardware store. Glue the lid onto the cooler, turn it upside down and cut a hole in one side (anywhere but in the middle of one of the long sides).  The Styrofoam containers used to ship meat can be turned into shelters in the same way and can, depending on their size, house 3 to 4 cats. If you want to get fancy, get a large Igloo cooler and, with a jigsaw, cut a five to six inch round hole towards the left or right of one of the long sides. The attached lid will allow for easy cleaning.


The cats' shelter will be warmer and cozier if you put loose insulating material inside. The material must be dry and loose, so that the cats can burrow into and underneath it.  Straw is best, while shredded newspaper will also work. The worst are blankets, towels or folded newspaper.  Because the cats can only lie on top of these materials, they actually draw out body heat and defeat the purpose.  Hay, because it's moist, can become moldy and some cats are reportedly allergic to hay and can develop nasal sores.  But do keep in mind, if you use insulating materials, you must be able to change them regularly in order to ensure they stay dry. 

Here's two other ideas for insulation:

Take a cotton pillow case and loosely fill it with styrofoam peanuts, the kind used to pack fragile items during shipping. Tie the pillow case closed and put it inside the shelter. The pillow case will conform to the cat's body and wrap her in warmth-capturing peanuts. (Note: as packing peanuts are now often made from starch, which dissolves in water, it's helpful to place the peanuts in a plastic bag before putting them in the pillow case). (This idea originally comes from the book Maverick Cats: Encounters with Feral Cats by Ellen Perry Berkeley.)

One exception to the rule that insulating material must allow cats to burrow in, rather than sit on top is the Fleximat Mysterious Purr Pad.  The pads can be placed on the floor of the shelter and will help to conserve body heat.  Sold in packs of two pads.

Extreme Cold

Claudia Allen of Winnipeg, Manitoba, Canada, lines the interior walls of her styrofoam shelters with a Mylar reflective blanket, which can be bought at survival stores as thermal safety blankets for people (in case your car gets stuck in the cold.) The Mylar reflects the cat's body heat back onto him and can make the difference in extreme temperatures, particularly in the more northern states and Canada. For a detailed explanation of how to build Claudia's Mylar-lined winter shelter, complete with photos, click here (pdf file).

Claudia also uses an outdoor heating pad in the shelter and an electric dish that she reports keeps water from freezing as low as minus 38 degrees F. These items can be found at http://cozywinters.com:  heating pad and electric bowl.

Caretakers have reported the Mylar blankets are also effective when laid on the floor of the shelter or attached to the walls.  They don't absorb and take away body heat like ordinary blankets when a cat lies on top, but instead reflect heat back.  That's why they're sold as emergency blankets for car travel in wintertime.  Mylar blankets are very inexpensive, usually costing no more than a dollar or two each.  Go to Amazon.com for a list of retailers and prices.  If attaching to the interior walls, you can use freezer tape or, for a more permanent fix, carpenter glue.  Be sure to tuck in any loose material at the seams so the cats aren't tempted to pull at or chew the loose material.