Large buildings in game. Who made?

Hi all.
Question regarding the large buildings around the map.

Who made these? An admin?
They tend to have no doors and there is no way some1 collected all that wood to build it.
Are people using a duping method?
I have been at it all day and the amount of wood piles I’m finding are pretty scarce.
Are these building there so we can bang up a door and claim it ours.
Or are they hacked ect. I’m just saying there is no way ln earth they have been built by collecting wood.

I have no life. Some days I play for over 24 hours straight - it’s very much so possible to collect loads of wood. Also having a team helps a lot.
If you have a giant base/camp people tend not to come close to it, meaning more resources for your team.
You really just need to find the “sweet spot” for resources.

The reason they have no doors is because people have raided them (broken down the door; stolen what’s in the house.)

There are spots in the game where the Lumber piles spawn like crazy. Just knowing where they are makes it all more easier. Also teaming up like Jackool said helps. One can gather while another defends.

I see tnx for reply lads.
I imagine I am in a bad place so lol
I’m pretty much next to the hanger.
Been enjoying it so far. Its nice to meet the odd lad that doesn’t automatically try and shoot you or axe you up haha.
I believe I need to relocate as I am prime suspect for getting broken into and looted ever half hour.

Any kind gentleman fancy pm me details of where is a nice loot place I could set up my little shack.