I am moving to a home away from my parents, and of course taking my 1 year old pup. He grew up with the other puppy we got at the same time, not the same breed but same age and they love eachother. What can I expect from him now being an only dog and not having that constant companion around? Plus he will no longer be living outdoors full time. I thought about getting a new dog for him, but thats a lot of work that I dont think I am ready for.

Thanks --Julia

Sounds like there will be alot of changes for both of you! First of all, do NOT get a second dog right away, maybe down the road, but settle in first.
THe first thing I would address is that the dog will now be indoors. I would start by taking the dog inside your current home for supervised time periods while at your current location. This way he can get acclimated to being indoors.
I don't know where you are, if there are any temperature issues. ( heat or cold extremes can be hard on a dog,what breed do you have?)
Well, good luck!

He is a siberian, and does not tolerate heat well. He will be outside when I am home and maybe down the road when I gone as well, when I know I can trust him not escaping the yard. I am thinking that first when i am gone I will just keep him either in a large crate outside with access to his dog house, or inside in the laundry room. His crate is made of wire and is for a giant sized dog. I understand that crates are supposed to be small and secure feeling, but he kept outgrowing them and so I just ended up buying a big one. He is never cold and I am in Oregon so its not that cold here anyways. He and the other dog spend 24 hours a day together, they even are exercised together.

well you may have a problem. My amstaff and my boxer grew up together. I dare someone to try and seperate them. For instance I took my amstaff to my first training session for schutzhund. My amstaff is 2.10 years old and my boxer is a little over 3. While we were on our way to the field my amstaff cried and was really finiky looking for his brother (the boxer). We get to the field he calms down a little and we start goofing off and playing. Then my wife shows up with our boxer and my amstaff started yelping, crying, pulling, clawing everything to get over there to him. We go over there and his tail wagging jumping and everything to greet his boxer brother. Then we put the boxer on the pole to watch the training and well my amstaff wouldnt do anything. He shuts down completely he just whines, cries I was so embarassed.

So I say screw this and I tell my wife to take my boxer home. After that he calmed down a little bit. Still ctying and what not. My wife told me the whole time the boxer was with her he was crying wanting to be with the amstaff.

Thats just one instance. There is another one where my boxer went to the vet to get neutered and my amstaff cried for the week he was gone. He was there a week because we use a vet at my Mother-in-Laws house hes an awesome vet. Anyway my amstaff cried forever even at night he hardly slept and always tore through the house looking out the window every chance he got when he heard a noise. So umm yeah have fun. I am dreading the day that the boxer dies or vice versa the other one will die of heartbreak.

Hi Julia - I just saw your post. I noticed your comment about leaving your Siberian in the yard when you know you can trust him to not escape....hmmmm, that could be a while
unless you yard is fenced like Fort Knox, there is a distinct possibility of your Siberian doing a little exploring and going to look for a friend. Unless your yard has been "Siberian-proofed" (which tends to give it the "Gulag" look) you are probably better off putting him in a nice secure, dig-proof(good flooring) and climb-proof(roofed) or wired over kennel run when you can't give him direct supervision outside. I would save the crate for inside the house when you can't give him direct supervision.
An adolescent siberian with time on his paws might decide to do a little landscaping of your yard and interior renovation to your home especially now when he doesn't have the other dog to interact with. Don't underestimate the siberian when it comes to yard escaping- they are masters at it and if they can't tunnel out they might jump or climb out. Separating two dogs that have been together might have some initial separation anxiety issues but extra training and attention will go a long way to easing that.
Perhaps a new hobby, dog scootering or something will give you both a good chance to do something together and keep him busy doing something physically tiring now that he doesn't have the other dog around. It's a lot easier to keep your sanity with a Siberian if you keep them really busy and tired!