Not too long ago, I was approached by one of the organizers of the Silver Linings Cat Rescue with a request to design them cat shelters. After some collaboration, it was decided that this plan would suit them best. The box measures 4′ (~1219mm) long by 2′ (~610mm) wide by 2′ (~610mm) high. There are only 4 sheets required for the whole job. This plan involves a 3/4″ (~19mm) of ply for the outside shell, 2″ (~51mm) thick rigid insulation for the middle layer, and 1/4″ (~6mm) for the inside layer. 3/4″ (~19mm) might be a little heavy for you, but shaving (half) that difference off all four sides isn’t complicated mathematics. This shell is easily modified to involve pressure treated wooden feet, ramps, swinging doggy (or kitty!) doors, even a light bulb with mason-jar shade to keep it heated when it’s near people’s homes. There is a lot of potential to do some really good work here. Hell, if your animal LOVES it outside, put one of these in for your dog or cat! I’m sure they’d appreciate it.
Anyway, onto how it’s built, eh?
We have some colour coding going on here, but that’s to match up boards with where they belong. As always, click on the image and if it’s original (like these are) it’ll show an enlarged image to full-size. If it is one that I’ve borrowed, it’ll link back to the source website. Please don’t hesitate to take these drawings and explore them. I welcome any exploration that you may have to contribute, to stimulate discussion. This is a rough-draft, a beta, please improve on it and share with the class!
You can see here the green, grey and yellow 3/4 (19mm) boards (though you can resize the drawings to whatever you like) on the backs of the stacks. The blue is 2″ insulation and the brown is 1/4″ plywood. The hole is lined with 4 pieces of 1/4″ ply, and the hole is 8″ square, so is the cut-out on the piece in the top corner, which is a “hallway” or “porch” wall. This functions as sort of an air-lock to keep the wind and snow from blowing all the way though, gives it time to melt and be more easily dug out by the critters and keepers. You can see on the upper, initial image that the lid is hinged, and can be hinged on ANY side. Bare in mind that hinges aren’t actually crucial, as this should be a snug fit and could be latched-down with any variation of these lock-down fasteners. There is no security concern with these boxes and fortunately the critters who may make use of these shelters have not evolved opposable thumbs and probably won’t want to enter the shelter through the roof. As I said, there is a tremendous amount of variation possible with this drawing, and we encourage exploration.
These colours match those in the assembly and completed drawings. The browns are the inside wood, all 1/4 (~6mm) plywood, the blues are 2″ (~51mm) thick rigid f oam insulation, though two layers of 1″ (~25.4mm) would obviously not significantly alter the design, it depends on local retail offerings. The grey, green and yellow are exterior, 3/4″ (~19mm) or similar if you wished to lighten the exterior shell. It may be easiest to finish the whole thing, pole a hole in the box where you want the door and cut it out as an afterthought, rather than worry about the exact location, which actually wanders away from the wood corner throughout the layers so they all line up when it’s assembled. You only need 1 sheet for the inner, 1/4″ (~6mm) layer, 1.5 sheets for insulation (or 3 sheets of 1″, 25.4mm), and 1.5 sheets of the exterior shell, in this case 3/4″ (~19mm).
The assembly is very easy. When all the pieces are cut out, just consider how it goes together. Each layer is centered on the board that sandwiches with it. The space must be allotted for the next layer to butt-up against it. It can get a little complicated, but just take your time. The L-shaped piece will fit in snugly against the door and provide the porch or airlock space.
Several layers of heavy enamel paint to keep it sealed against the elements, and maybe some strips of heavy plastic to act as a door/air barrier in the two doors. A space for a light can be installed on the roof via a low-profile light bulb receptacle or pigtails and can be plugged into your home for light and warmth for your critters. It may take a little wiring, but an exterior lighting plug wired directly into the light bulb inside may provide the safest solution, where plugging an extension cord into the box, and into your home is the only switch that is necessary.
It can be built for around $60.00 CAD, and with many options, please explore! Enjoy and shelter animals from the cold. Oh! Don’t forget to have your pet spayed or neutered, to help control the number of strays. Please get a pet from a shelter and NOT a puppy/kitty mill. Please build these shelters to assist in spay/neuter/release programs to help control the feral pet population. Every stray you save could save thousands of lives from elements that their breed is no longer designed for. Please do your part.