One night, I fell into a YouTube rabbit hole of saw mill videos…which is to say making one’s own lumber is just another DIY woodworking project, because Harbor Freight sells sawmills.
https://www.harborfreight.com/saw-mill-with-301cc-gas-engine...
https://www.harborfreight.com/saw-mill-with-301cc-gas-engine...
An axe and a broadaxe and a chalk line (though people originally just used charcoal).
Making beams is not that hard, especially if you have lots of wood and not a lot to do in the winter.
Whenever someone says, I want to write X program from scratch. I’m going to send them this link.