Many customers do choose to insulate their log cabins, though this is not a service we offer, nor something we can offer much advise on.
Our cabins are made from 44mm thick timber, which already provides plenty of natural insulation, however we know that some customers may wish to go a bit further and add their own. The most popular option seems to be using 1” thick insulating foam board such as Kingspan and fitting this beneath the roof boards, though you may lose some internal height doing so.
Please make sure you read through our 10 Year Guarantee terms to see if any changes/additions you make will affect your eligibility: https://www.powersheds.com/10-year-guarantee/