Hello there and first of all welcome

Since rabbits are natural burrowers, they will be curious to any sort of dark looking shelter you provide for them. It may take them a few days but I should think that a secure hide-out, be it a dog kennel, hutch with an open door or something, they would be more than inclined to go in it and use it for shelter. For the temperatures you are talking about I don’t think heating is terribly necessary, rabbits cope with cold temperatures far better than they cope with heat, and if you do provide a hiding place for them, you could simply stuff it with hay or straw so that they can burrow into it and stay warm more easily.

Are you looking to lock them in the shelter at night? Or are you simply looking for a place they can escape to when they feel cold? If you’re looking for something to lock them in, some people use timber garden sheds for their rabbits, and it would be fairly straightforward to install a heater in one of those if needed. Training for something like that can be as simple as timing an evening meal for the time you want them to go in the shelter and feeding it in the shelter (or next to it in the beginning if needed). Then when they run over for their meal, they run to the shelter.

I agree with Azerane. Bunnies like tunnel-like structures for reasons that must be genetically coded. Anything remiscent of a burrow/warren will attract them. There should be two “door-holes” because bunnies always want an emergency exit.

I live in Sweden where winters can get very cold. It’s still legal to house bunnies without extra heating (we have strict laws regarding the keeping of animals). The law states a rabbit must have an insulated hiding-space, elevated off the ground (by a foot or so, so cold doesn’t penetrate from below), shelter against rain wind and snow and direct sunshine, adequate bedding material (f ex straw), and during times of below zero Celcius degrees, be provided with fresh, warmed water twice a day (because water will freeze). In Sweden you must also provide the rabbits with a a shelf they can sit on or hide underneath. The shelf must be big enough to allow all rabbits housed together to sit together.

Does it get gradually cooler in Arizona? If it does, the buns will adapt by growing very much thicker fur. They will need some extra food (more pellets or f ex whole oats).

Chickens can’t be kept without extra heating in the winter, but rabbits are very good at keeping warm.

and if you do provide a hiding place for them, you could simply stuff it with hay or straw so that they can burrow into it and stay warm more easily.

Yes, straw is a very good insulator. They could burrow into that. I suppose adding things like a couple snuggle-safe warmers wouldn’t hurt.

So you don’t get any wild life or other domestic animals scaling the walls? We had a Arizona member here who used to post regularly and often go photos of various animals entering their yard.

@Bam, Im very impressed that Sweden has these laws!