Adding light to scene makes everything laggy!

Everytime i add light to my scene it makes it exstremly laggy. Yes i build the light and apply it but when theres more than 2 lights in my scene it begins to lagg. Even if i package the game the scene is verry laggy.
Anyone might have an idea? :S

What are your System Specs?

Running Unreal 4 effectively isnt something a low end computer is going to achieve.

What type of lights are they? For example, movable lights will have performance issues whether or not lighting is built, and static light never has any performance cost. And point lights cost much more than directional.

When you add a light even if it’s static it’s going to render with real-time preview shadows which is not going to run as well as it would once it’s baked.

I added point lights, how do i add static lights or baked lights?

My specs are:
Intel(R) Core™ i7-4790 CPU @ 3.60GHz 3.60GHz

What is your GPU?

Go to the details panel of your selected light. Under the transforms you’ll have the Mobility of the light: Static, Stationary, or Movable. Static and Stationary lights use Lightmass (prebuilt lighting) to get great looking shadows in the scene. So after you place a new light (which defaults to Stationary) you need to Build the lighting (look toward the top of the screen for a big button) in order to have it precalculate light and not act as an expensive dynamic light.