Massive Light Bleed

Ah, Arch Viz, then you need super quality.

Well in the meantime I’d recommend looking at these two links that both deal with lighting for Arch Viz

https://ue4arch.com/ue4archs-unreal-engine-4-lighting-workflow-part-1/

the second link here has alot of trial and error methods so you’ll have to sift through it all to figure out what does what but the first link should help you to start off.