Barna and his wife live in San Francisco. Their neighborhood has a colony of feral cats. Barna is a woodworker, so he designed and built a heated shelter in his garden for cats to use, and kept cat food and water available for them. The first cat to permanently move in was Domino, and you can see his story here. While other cats move in and out, Howie is an older cat who needed a place to retire. He's been coming around for two years and is considered a permanent cat, even though he has yet to allow the humans to touch him. Howie is a little stuck in his ways, but he has a comfortable home now. You can keep up with the cats at Instagram.
Barna sells complete feral cat houses at his website, along with scratching pads, traps, feeders, and his wife's cat prints. If you want to build your own feral cat house, he offers the plans for free.