http://coeqa.diegobao.info/question/5776550c3310296adc58ea85
I’m not going to walk through it end-to-end, but the process is creating the individual resources, cutting down the lumber planning them into individual boards, taking those boards to construct the framing pieces, take the framing pieces in order to create walls and ultimately taking those walls and using them to actualise the blueprint you’ve laid down. So it’s going to take time as you have to gather all the resources and each of the individual components need to be made.
It’s not going to be in your inventory either so as you make them you’re probably going to be leaving them all around the property for other people can come in help you construct that. You know houses are designed to be a multi-person endeavour not something you’re going to be doing by yourself, and in terms of how long it’s going to take. It depends on the size of the structure. I expect it would take about as long as it would in our world.
If a house takes 8 months to build, then realistically it’s going to take you about that long in-game as well. You’re probably not going to be doing it 24/7 obviously, but if you spend a couple of hours of play, per day, in the course of a week then maybe 3-days to build a reasonably sized house. Longer if you’re trying to build an epic castle or something like that.
CoE sometimes gives up realism when it doesn't add to the game, but in this case it seems they are definitely preferring to add the realism factor :P You should have to account for all parts of the lumber process, although to be fair I think a lot of early woodcraft was done on site with hand tools, to include roofing shakes and planing large beams. Cutting into boards would likely require a mill though
Edit Poldano has a good point, cutting boards could likely be done on site too. I think I was overcomplicating the idea of a large saw in my head :D