1. Shelter from wind and rain: New Zealand and Californian breeds- the two kinds we have- are cold-tolerant creatures, and are fine with temps down to 20 below zero. They can't stand wind or getting wet, though- they will get sick and die. Colorado is a windy place. Since we've lived in our current home for a couple of years, we were familiar enough with the storm patterns and wind gusts to know they needed solid walls on the north and west sides of them.
2. Exposure to sun in the summertime: These same rabbits that can tolerate the cold cannot tolerate the heat above 90 degrees F. It goes above 90 frequently in the summer, so we needed to figure out how to shade and cool them. We placed the condos at a spot in the back that maximizes their shade from the tree foliage in the summer, and I am building a raised garden bed in front of them where I'll plant thick, tall-growing edibles to further shade them. By tilting the roof, the heat can escape, and we have vents at the top. The burrows provide a stable temperature underground as well, which they take advantage of sometimes.
3. Exposure to sun in the wintertime: To keep rabbits fertile in the winter they need lots of sun. In Colorado, the sun migrates to the south in the winter. We placed the screened doors to the East and cut windows in the south walls to allow maximum sunlight. Foliage falls off and the harvest gets taken down, so there is more exposure to sun.
4. Socialization/cool idea: Living in solitary confinement isn't fun. We decided to place only chicken wire (and reinforced wire underground) between the rabbits whose units connect, and build a shared hay manger. This wire wall also helped with circulation in the hot summertime, and additional sunlight in the winter by making it more open.
5. Sexing and separating kits when they're ready for weaning: We built a second story on the second condo, with one side for the males, one side for the females. There simply isn't room for them to keep living with the doe after 8 weeks. We designed the upper level for minimum time spend cleaning- the poo falls through to a masonite board that's treated with garage floor paint. It's slanted so the poo rolls down into a gutter on the outside of the condo. All I have to do is sweep it into a bucket.
6. Environmental footprint: All materials used on these were scavenged from Resource here in Boulder, a re-use/upcycling center for home improvement supplies. Even the paints, I picked up for free at the Center for Hazardous Recyclable Materials (CHaRM). I got the food bowls from thrift stores. The only thing I bought new were some of the 4x4s and 2x4s (they were in hot demand and hard to find), the hasps used to lock the doors, and the water bottles. Oh, and the cement supplies. Most of the rest of the wood, hardware, flagstone, rocks, bricks and all the roofing materials were scavenged.