Insulating a Log Cabin (built from kit)

[daryah]

Well, just about finished building a log cabin from kit [url]http://dhlogcabins.co.uk/uk/product/83/445/severn-5[/url] see this link)

Did not get the insulated option coz of big ££ - (Did get the floor insulation but have found out since that I paid 4 times more then I should have for it - Any hoo, live and learn..)

Thinking about insulating it at some point and the company's idea of putting the kingspan insulation inside and another free floating wood wall is one idea, but...

also, thinking about getting pvc-u cladding and putting foil backed kingspan both *on the outside* - this will also not take away from internal floor space and should be maintenance free for many years to come I hope (not that I mind maintenance)

the main design right now would be to do this on the back and two sides, but my question is can I get away with leaving out the front and insulating on the inside ( insulating plasterboard or kingspan + floorboard/plasterboard) - main reason for this is to leave the wood effect intact on the front for its aesthetic charm

Now, am not a carpenter and am not sure how this cabin would develop
over time (or any similar cabin without modification) - have built it on 6 inch concrete base and it has been built to spec pretty much - but as the front will be exposed and the other three behind insulation+pvc, will the differing moisture levels between the front and the other three sides have an effect as to how this cabin ages? Each wall side is built of t&g and is connected to the other walls with overlapping / criss-cross style connector (see pic on link) - will the front expand and contract more then the other eventually causing breakage? Or am I worrying too much?

One other thing is that since PVC cladding is also a bit of ££ and the rear and left side of the cabin are fairly out of sight, I was thinking of just putting a weatherproof membrane of sorts. Any ideas?