Having issues with scaling and Lights

I’m creating an architectural walkthrough. I’m getting stuck on the scaling issue. I built everything in my 3d program in a 1:1 scale straight from blueprints. I then for some odd reason (a tutorial told me) set the scale in my FBX export to 5. So I’m guessing everything is now 5x bigger than real life. My problem now becomes when I place lighting I have to jack the power up to max and move the light closer to the ground to get even the slightest illumination. *See photo. *

Should I select everything and scale it down or re-export each element with a scale of 1.

In Unreal 1 unit = 1 cm, so make sure you adjust that in 3ds max. But otherwise you can select all your meshes in ue4, group them with (CTRL+G) change the scale of the whole thing, ungroup (shift+G iirc) and you should be fine.