Here's a 1200-yr old wooden church: https://en.wikipedia.org/wiki/Greensted_Church https://en.wikipedia.org/wiki/Greensted_Church Protected from fungus (rot) a

Here's a 1200-yr old wooden church: https://en.wikipedia.org/wiki/Greensted_Church https://en.wikipedia.org/wiki/Greensted_Church Protected from fungus (rot) and insects, wood can last indefinitely. How to achieve that, of course, varies widely.