I've just needed to bring 2 of my kitty's that were being fostered back home. My home also has 2 fully grown Rottweilers, so I needed to create an outdoor enclosure for them that keeps them safe inside and the dogs out. My kitty's however, always lived inside the house, but it's too risky for me to allow them in now with the dogs having access inside. I've built a big and comfortable cat enclosure, with couches, a big litter,toys, beds and wall mounted hideaway tunnels. They still cry to come in occasionally and hate to be left alone. Am I doing the right thing by keeping them there? There are 2 of them in the enclosure. I don't really have options and I need to make sure they will be happy living the rest of their lives inside the enclosure. Please advise.
The cats will survive, but they will be unhappy.
Maslow's Hierarchy of Feline Needs start with the regular food/shelter/water/litterbox and continues with safety and security. After that, they have social needs. Your enclosure can guarantee the first two levels, but not the third one.
Such a luxurious enclosure would allow them to spend quality time on their own. They can also play with each other as well. But domestic cats still need a human companion from time to time. This is why stray cats come and expect pets, even if you don't feed them. Socialising is important. Socialising with other cats is great but it doesn't make up for the lack of human interaction.
You can alleviate this problem by personally being in their enclosure for some time, maybe 30 mins to an hour a day. If you can take your computer and watch a movie with the cats, that would be fantastic.
At the beginning, there will be some time to get used to the new settings. Cats have very well determined routines. There is a specific time every day for eating, relieving, grooming, playing, petting and cuddling. Therefore, the minutes you spend with them might not be their preferred time to play, pet or cuddle and they will keep crying to get to you when their preferred time comes. But eventually, they will learn how to deal with this.
I never had cats and dogs live together, so I suggest you to ask another question to inquire what can be done to have them at the same time inside the house. But your cats, with the new settings, will be unhappy for some time.
My experience is with farmyard cats in Western/Central Europe.
In contrast to @C.Koca's answer I'd say human companions often do not rate that highly with them, they are very independent. But: they are not kept in enclosures. Among some other things that means they can come and be sociable when it suits them, and go away when they don't want to be sociable (applies to humans, other cats and potentially [= best case] dog/other animals). It also means that they are not bored. When then want to seek an adventure they go and do so.
Here in Central Europe, there is no problem keeping farmyard cats all year round "outdoors". The climate is sufficiently suitable for domestic cats to go wild again (this is a concern since they are not only using the same habitats as Felis silvestris (European wildcat), but they also interbreed).
Farmyard cats go and find appropriate shelter. E.g. our previous cat clearly had a nice horse-heated place in our neighbour's stable (you could smell that every so often when she came along). We also once had a cat who would curl up "in" the dog.
If the cat is always outdoors it grows a proper winter fur which an indoors cat that only has outings of a few hours at a time won't. Starting to keep the cats outdoors in November when they've been indoors all the time before is not a good idea in the climate we have here - they miss something like 2 months of adaptation by gradually increasingly colder nights. The colder your climate gets in winter, the more important it is to not disturb this cold adaptation by letting the animal indoors.
And if they are this year's kittens, they are still far from fully grown and likely still have quite thin fur - therefore heat loss is a bigger issue than with fully grown cats that have been outdoors all the time since summer. You'd need to provide them with a very well insulated or even heated spot since your enclosure lacks features such as the stable or a convenient nice dog that farmyard cats typically have (and if not, they have the option of emigrate to a better place - and they'll certainly do that.).
Also, for fully grown cats with winter fur I think you'll find that like outdoor dogs they'll need substantially more feed when it is cold.
There is also the question of what you'll do when they need to stay indoors occasionally (sick, or e.g. if the night after vaccination happens to be cold).
If at all possible, I'd like to encourage you to get the cats and dogs to learn getting along with each other.
All I said above above feed needs and winter fur growth applies to the dogs as well (Rottweilers do have proper underwool and here, quite a number of them "works" as outdoors guard dog e.g. for property in industrial zones or on isolated farms). And if it comes to cold temperatures, they have a better body weight : surface ratio than the cats due to their size (OTOH, I believe cat fur of the same length will probably insulate better, since cats have far more hairs per cm²).
I found some recommendations for a minimal legal standard for the room size for 2 cats, which would be around 15 m² for 2 cats that get along well with each other, at least 2 m high and properly "furnished" (with multiple levels, ...). The usual recommendations for nicely keeping 2 cats indoors speak of the cats having access to 50 - 60 m².
For comparison, the dog bylaws require a minimum of 16 m² enclosure for Rotweiler-sized dogs who are to stay in that enclosure most of the day (sufficient contact time with their humans and other dogs and sufficient physical exercise outside the enclosure is anyways required).
So just in case: if you think you don't have sufficient space for an enclosure for the dogs, you also don't have sufficient space for an enclosure for the cats.