Okay - this is how I trained Bailey - and we were very successful.
1st - Both Hubby and I work - so we kept Bailey in a pen while we were gone - about the same size as yours (4x4). Since we were not there to supervise her during the day, she peed all over and chewed her pee pads. Yes, it was aggravating - but I expected it and I accepted it- I just cleaned it up every day. 5 minutes - no big deal. I rotated two throw rugs daily. When she was about 8 mos she quit messing in her pen. I know you said he is a year old, but he is also new to you and has never had any training - so I wouldn't be concerned about his pen right now - just accept it and clean it daily. When he learns bladder control from your potty training, he'll learn to keep his pen clean.
2nd - we did do some crate training - but I was adamant that I didn't want Bailey to spend her puppyhood in a crate. So, we blocked off the family room, removed all hiding spots and laid down several blankets. Then we watched, watched, watched her. All eyes on the dog! If we had to turn our attention away from the dog, then the dog went into the crate. Bottom line - watch the dog so you can immediately correct behavior - or put him in the crate. Don't try to do two things at once. Time invested now will result in a lifetime of trust.
During the training, I immediately swapped out any soiled blankets to remove the odor. I also put down a service bell - so as we scooped up Bailey, we said "outside", took her paw to the bell and rang it. Now she rings the bell to go outside!!!
I'm not a fan of "take the dog out every 2 hours" - that doesn't train the dog, it trains you. The bell is key to this system as it allows the dog to tell you when it needs to go outside. Yes, expect some bell abuse. After you have successfully trained your little one - you can tell him "no" if you know bell abuse is involved! lol
It was hard work - believe me - it wasn't easy. But both me and my husband were not going to tolerate pottying in the house - so we both dedicated ourselves to the process. We saw concrete results in 2 mos and she was reliable in 4 mos. After 4 mos, we picked up the blankets and opened her up to the kitchen, then slowly opened up the rest of the house. She's had free run of the house since she was a year old.
If I had only one tip to give someone - then I would say do not remove your attention from the dog while loose anywhere in the house. It will quickly learn to pee behind your back (or go in a quiet corner, etc.) and once that starts, your chances of success start to decline.
Good luck!!
