I may have found an answer, or at least it might be specific to my own stupidity. So I decided to build the light just to see what the light map would have to say about the issue… and it said my light map was too big. Ok, well what’s too big… I have 32GB of RAM and a GTX980M video card(8GB). Well, all my static meshes, including ALL my foliage was set to 1024 for lightmap resolution. I had over 1000 pieces of foliage and other static mesh actors(modular walls) in this particular level and no other level. That would explain the sudden memory consumption. That would also explain why it took about 10 minutes straight just to build the lighting in this one level. In case anyone might have a similar problem or assumes they are randomly having a memory leak, check your resolution settings. All of your settings related to graphics, resolution, lightmaps, etc… They add up very quickly, especially if your lightmap is 30 times higher than it needs to be.