As a rule, log cabins are not insulated because the thick logs offer enough natural warmth. Each solid wood structure captures air bubbles, keeping the cabin warm in the winter months and cool in the summer.
Your base should be flat, square and level. Concrete bases are ideal because they require little to no maintenance. But paving flags or decking will work just as well.
As a rule, log cabins don't require foundations. But they do need a solid base between 80 and 100mm deep to avoid sinking into the ground. This could be made from concrete or paving slabs. Or be arranged on a patio or decking.
It generally comes down to the thickness of the wood cladding. The wood used on a summer house is between 7 and 12mm thick – similar to that of a high-quality garden shed. While the cladding on a log cabin can be up to 70mm thick.