In Ian Dunabrs book 'Before and After You Get Your Puppy' he talks about 'errorless house training' where you use both short and long term confinement to aid house training. Short term confinement is using a crate, long term confinement is using a puppy pen, with the crate inside and a toilet area (he suggests using turf or grass).

The idea is, you keep the puppy near you, but in short term confinement when you're around. Every hour you take them out to toilet, praise them when they go, and any play times are immediately after they pup has ben outside to toilet, then the pup goes back in the crate again. Obviously it works best for younger pups who sleep most of the time they are not eating or playing! You would use the long term confinement if you need to go out and leave your puppy, or overnight. It also enables 'errorless' chew toy training, as the only things the puppy has access to chew he is supposed to chew, so he learns to chew the correct things.

Having said all that, it is quite regimented, and personally, not for me.

I personally wouldn't wait outside with a pup for an hour. I go back inside after 15-20 minutes and keeep a very good eye on them, trying them again 20 mins or so later.

Have you considered he might be holding on as he likes going in the garden, and weeing or pooing means he has to come back in? Most people take their pups back in right away once they have been, so pup thinks wee=go back indoors/play is over. Once you do catch him going, (and I'd be inclined ot ignore him until he does go) give him a treat, and then play a game with him for 5 mins before taking him in, so he learns wee= game playing.