ArchViz lightmap Artifacts/issues

I’m getting dark and light edges where geometry meets up, mostly in corners of walls and where walls meet the floor and ceiling. The geometry is single sided and is not overlapping.

Also in areas where objects meet I get really blocky overly dark shadows, for instance where a door meets the floor. The floor has other areas where the shadows are lighter with a lot of gradients so I know the light map is high enough, but in this area I get really dark blocky shadows.

This is happening all over my project and I cant figure out why. I have upped the res, upped the quality, cut my uv’s made my uv’s continuous, etc…

Is it possible to get a better quality than this or is this a limitation of lightmass?

Lightmass settings:

scale .1
bounce 10
sky bounce 10
quality 10
smooth 1

Any help would be greatly appreciated.

There are multiple solutions to this problem. I ended up covering my model with a cover mesh. That way the corners (and the model of the building in general) isn’t directly exposed to the lighting. You can use a very low LM resolution to use a very low amount of resources.

You could also snap the lightmap UV’s to the grid of the corresponding resolution. (https://www.reddit.com/r/UE4Devs/comments/246whl/the_most_important_thing_about_lightmaps/?st=jfffzf8t&sh=515252d5)