I′m trying to repair the main house roof in sanctuary. Any ideas how to do that properly? Also, how do i add a door?

No idea how to repair the roof. I spent hours trying to build a shelter before giving up. I can't move when I'm in build mode.

To add a door you have to be outside the building (that you built) but I haven't been able to build a door on the houses that are built by the devs.

Did you try both arrow keys and wasd?

Yeah I couldn't get a roof on either. I found no way to spin around the roof piece to lay it on the last section of the roof so the opposite corners of my 'house' had no cover.

Personally I think the whole shelter building thing is broken BADLY. If there are ways to actually make what you want their did a great job of hiding the commands to let you do it. Hell I spent 30 minutes just trying to get my flooring to line up properly with the cement slab. Finally just gave up and build a house on a slab crooked. Then I couldn't finish the roof and just gave up. Hope those settlers like sleeping under the stars.

My first attempt ended up so shabby and rambling I just scrapped it all...just doesn't seem like a very intuitive system as it stands. What really bothered me was the empty windows, as we can make flooring and furniture but still have these empty window frames that as far as I can tell can only be covered with more walls.

No, just the arrow keys. I have to play in a window because of the ratio and I'm afraid to mess with my tv settings. My hit points, ammo count, and weapons keep disappearing from my hud, but I can see to pick a lock.

You might be able to place a FLOOR on that hole in your roof....

I tried to create a metal house using corner pieces and side pieces that arched a bit at the top. They locked together nicely (although did not fit on the concrete slab evenly).... and I was even able to get the roof to snap into place very quickly. The only problem I had was the DOOR. The door kept snapping to the "interior" of the corner pieces, which left a hole between the doorway piece and the exteriro of the corner-wall piece, so you could just walk into the house that way.

I finally just ended up slapping a pre-fab wooden building and then I placed some stairs on the upper balcony which switch-backed up to a height that, I think, took me out of the "building zone" entirely. Tried to make a floor / room up there in mid-air but could not get it to work. Did manage to put some side-railings on the staircase landings, which should make for handy sniper positions.

I built stairs up to the top of the building, then walked around laying the roof like floor tiling. .. I then scrapped the stairs.

I did not touch too much into this feature since it was quite difficult to move things on the Xbox One for building. I might try it again when I start my second character. I might start it today since I love starting new characters and I want to hear how the male Sole Survivor voice is.