Is this lighting normal?

My walls have a strange lighting to them around all of the edges. Is this normal? How can i go about fixing this?

try to increase lightmap resolution

How much do you think i should increase it by?

depends of module size - if just one wall make it 256 or 512, if not make it. as minimum needs to separate walls, roof and floor. build light in production mode.
and make sure that your have correct UV Islands if your walls not separate for example Unwrapping UVs for Lightmaps | Unreal Engine Documentation

What do you mean “if just one wall”? Can i send you my project so i can understand?

I tried what you have said and achieved this. Still looks weird with the abnormal shadows.

Any idea??

where is abnormal? corners less bouncing in life. also you can increase bouncing in the world settings.