Just to add what others' have said - crate, crate, crate. Do not underestimate how useful they are both to avoid further damage and as a helpful tool for your dog and for you. It sounds like sep anxiety to me too, especially if he's relatively new to you. I have a 9 month old who has been with me since pup and she still destroys the place on the rare occasion I have let her loose in the living room. It WILL happen if he's a chewer, and you can't blame him if you're aware of this and choosing to leave him out in a big space with plenty of things for him to chomp on. It will only make you angry and he may well pick up on that and get worse through anxiety. Dog gate I also agree with - use one to confine him to the kitchen or another area where he will be a) safe and b) can't do much damage.

You can buy a CRATE online, much cheaper on ebay http://stores.ebay.co.uk/doghealth-stocknutrition (I use two diff sizes of theirs and the crates are fantastic)

You can buy a DOG GATE from pets at home or any other large pet shop, or from ebay

Honestly, you will wonder why on earth you never used a crate once it's in use and you have control over the chewing, then you can work on the chewing with chew toys and some behavioural training, and time! Best of luck.

OH MY GOD that could have been so much worse

Didn't realise he is so young. He will chew for a good while yet, give it at least another year. Sorry to be the bearer of bad news, for some reason I was under the impression he was older than that. I used to have dobies, and they were always about 18months - 2years before they stopped chewing. He is very much a baby yet, and that is what babies do I am afraid.

My lot don't chew but still don't get the run of the house, they're confined to the utility room with a dog gate when I go out. I do it as much for their safety as my own peace of mind. I'd give him something he can chew on such as a kong or two and leave him to it. I find all of mine just doss when i'm not around. I have found though that dogs prefer to be behind gates rather than closed doors.

Oh my good God!!!
yea think Ben will be in the hall from now on. Will check out the crates (Although where I am going to put it I dont know, we don't have a lot of room)

Once again thank you all so much for all the good advice. As I said I feel sooooo much better now. Now I know that I have not chosen the doggie version of Damien And I am not alone in the Universe!!!

I agree with Chris - if you can solve the underlying problem it will help the rest of the unwanted behaviours as well.
Just to add - Your dog is at an age when they will probably exhibit their worst behaviours - they`re still imature but they`re starting to want to throw their weight about. In a word - they`re Kevins. It`s not a co-incidence that most of my rescue GSD`s have been around 1 year old. Personally I wouldn`t crate an agitated dog, but I would restrict their access - and maybe look at ways to calm their anxiety.

Selkie never grew out of this phase, she's 12 years old now and still cant be trusted to have the run of the house when we're out. She doesn't chew through boredom (she has lots to do) nor anxiety, (she'll happily go pick something up and chew it in front of us when we're home)... she chews as far as I can tell, because she likes to. She likes plastic things, like carrier bags, mobile phones and remote controls... though a couple of years ago she developed the more dangerous habit of clothing and socks, I say more dangerous, because it has nearly cost her her life on two occasions.

We tried everything to train her out of it and we tidied everything out of her way, but she's a very intelligent thief. Selkie will not be caged, she goes mad, so after some consultation with the vet we have an open mesh muzzle for her, she can drink through it and can open her mouth to pant, she has to wear this at night when we sleep and if we are going for a walk places that have plastic bags or too much litter, it has to come with us in our backpack wherever we go in case she gets a fit of the munchies while we're out.

When they are left at home, they have a day kennel and run of the garden outside. I cannot leave them in the house. I don't like to leave Selkie in the muzzle when there's no one here to make sure she's safe, and with a puppy as well, it's just easier to keep the garden safe and clear of rubbish and lock them all out.

Was just going to say that is the age most dogs end up in rescue as people have no idea what they are taking on sometimes, they expect this cuddly bundle to remain like that, and when they change into a mixture of Damien and Kevin and it carries on for ever and the house is trashed, it causes 'tensions' (to put it mildly) in the relationship and the poor dog goes.

He's still a puppy, and he'll probably get better with time. Loki chewed when he was a teenager, but he only trashed my daughter's things! I think he was jealous coz he usually did it when I was bathing her or reading stories, things like that. He's now two and I can leave him anywhere. I wouldn't be without a crate for a pup though!