An acquaintance of my daughter staff bitch has recently (12weeks ago) had  pups all sold apart fom the one they are keeping I belive it is their first and only litter (I hope they really mean that)
She met them yesterday with the little boy who seems extremely nervous but very friendly and just wants to be cuddled. Apparently he refuses to go out of the house even into the garden. His house training is going ok as long as they take him out and then bring him back in otherwise he just sits there.   Same if they try and get him to go out of the house on the ground total refusal to move. My daughter says so much so she wondered if his legs were ok but apparently indoors he tears around and behaves quite normally.
The owner is using treats to try and pursuade.They were talking about taking him to the park and walking away to see if he followed (not a good idea imo) Apart from a good socialisation class which I shall recommend (an apdt one) any other tips.?
Was half tempted to have him with me for a few hours to see how he would go with gentle socialisation with ours but a bit concerned I may bite off more than I can chew !

I take it that they still have the Dam of the pup too? 

So you are saying the pup is nervous of going outside in the garden in it's own home too? Very strange. Unfortunately the idea of you taking him for a while could be a mistake if he is afraid, taking him from the people he is learning to trust may well frighten him even more.

At a guess I would say that when the litter was produced the pup was just not introduced to the outdoors. I wonder where the litter was reared? Pups should be experiencing the outdoors with the dam and other pups from 5 weeks onwards. Maybe due to the winter and it being their first litter the breeders did not know to take the pups into the garden for toilet training and exploration and confidence building, so now the pup has no confidence at all outside and does not count it as part of his territory. This you would expect with some pups on walks outside their territory of the house and garden; pups can be worried and may not have confidence when first leaving the home as everything smells different and they can pick up scents and sounds they are not used to, to be nervous here is understandable, but in his own garden where he was reared he should not feel like this at all. 

Nevertheless, IMO the dam is the key here, they need to get the pup to go outside with it's mother, she needs to go on outdoor walks with him if not already too to give him confidence, it should be natural for him to follow her about and stay close to her, they also need to do the same in their own garden. The owners need to start spending more time in the garden involving the pup in play, taking his toys even his bed out there and just sitting out there ignoring the pup until he comes out to visit, he needs to feel it is safe.

Maybe with the dam with them as well they could all meet up with you and socialise with your dog, that would be good for the pup too he needs a lot of meet and greet, are they taking him to all sorts of places to hear noises cars, shops, people etc?

He's only 12 weeks, he will come along, maybe he just didn't get the start he should have...............

Thanks carrington I will pass on the advice. I have decided as hard as it is not to get involed with taking him for a few hours. Yes they do still have the dam and I really cant understand why he isn't wanting to follow her about. I dont know how the litter was reared. They are acquaintances and know little about their domestic arrangements I feel the litter was one of those one off ideas not experienced breeders . I have known of pups being reluctant to go outside their territory and first time on lead for a walk is daunting but refusing to leave the house even for the garden then refusing to move when put outside even odder.
Will pass your ideas on and hope he makes some progress