Outdoor Facilities at Cat Rescue Centers

Cat shelter with outdoor facility in Brazil. Photo by fofurasfelinas
This is an article about cat shelters anywhere in the world but the ones that I most often read about are in America. I recently stumbled upon an article about the cats at the McKean County SPCA.
An outdoor facility for the cats is going to be opened on June 22, 2014. The facility includes trees for cats to climb on. We are told that it is going to be a catio, which is an enclosure that straddles the indoors and outdoors. It is a way of allowing cats to explore or sense the outdoors safely. I prefer pure outdoor enclosures.
One of the organisers of this project is a local resident, Grant Orris, who says,
“They’re getting fresh air. They just get a lot of anxiety.”
I wholeheartedly agree with him. Apparently, a dozen people have helped to build the enclosure. Other people donated funds totalling $12,000.
Well, this got me thinking about facilities at cat rescue centres in America or elsewhere for that matter.
How many of them – and I don’t know the answer – have outdoor facilities which are safe? How many cat shelters have indoor/outdoor enclosures where a cat can smell the outdoors and feel grass under his feet; where a cat can climb a tree and scratch the same tree if he has his claws.
There are scientific papers on the ideal size and structure of the cage for a rescue cat at a rescue centre in order for the environment to be adequate to avoid stress. Stress is a precursor to illness because it affects the immune system. Stress also makes a cat less adoptable because it makes him agitated and therefore more prone to aggressive behaviour.
There are a lot of potential downsides to keeping a cat indoors full-time in a cage at a shelter and a lot of these negatives can be counteracted by allowing a cat to go outside in safe conditions. However, outdoor facilities where cats mix should be managed because it forces cats who are strangers to interact which can be stressful as well. The ideal is, probably, to initially keep newbies separated and then introduce them to the outside, mixed facility.
I suspect that a lot of cat rescue centres are in urban environments where there is no possibility to construct an outdoor facility.
If that is true it begs the basic question whether there should be more care exercised in deciding where to locate a cat rescue centre. America is known for its space. I’m sure there is no shortage of space in out-of-town areas which are still easily accessible by the public. I wonder whether these places are more suitable to site a cat rescue facility on the basis that there should or could be room for outdoor facilities.
The contented and healthy cat is obviously a more adoptable cat and the more cats that are adopted and the less cats that are euthanised at cat shelters, the better for everyone concerned.
Can someone help me? Can someone tell me how unusual it is to see outdoor facilities at cat rescue centres?
I may have a jaundiced and distorted idea of the classic US cat rescue centre. I see the building as in a semi-urban environment, perhaps in one of those sprawling areas outside of the centre of town, perhaps in a shopping mall area, where there is no space out the back of the building where an extension could be built that would allow the cats to its floor the outside safely. Am I correct? Please comment.