Do you know any mod that can tackle things like that?

imgur.com/A7InoYC

Bascially I want to place that item despite collision.

Also the area for building is way too small, can we got something bigger please Bethesda?

More props

More props

More props

...and once again, more props.

There are roof segments with a corner missing.

And yes, I know what you mean. I really want to be able to replace roofs and repair walls on existing houses at some point.