creating buildings in UE4 OR BLENDER?

hi I am new to using UE4 … well I haven’t used it for a while, so I do not remember much about how to use it .

I want to create buildings, but im unsure if I should create most buildings , if not all in UE4 or Blender.

which is a better choice?
should I learn blender in the meantime? or just use UE4 and not bother with blender?

Use UE4 to block things out for scale and layout, and then make your final meshes in Blender. The BSP tools in UE4 are difficult to use for things beyond very basic block modeling, Blender has complete modeling tools.

But to save time would it be Easyer to just make the mesh / obj in blender and import ?

Yes, that would be a time saver if you already know the map layout and scaling.