I downloaded the demo content on UE4 marketplace yesterday, I’ll try it today to see what I can use for myself.
For the blueprints demo, I already visited it and yeah, there is an epic door that is opened in the two sense (one go to the left and the other to the right) but the door I use is a simple door as many in games, you open it in only 1 sense, forward of backward so I’ll see where I can learn this.
For blender, I’ll use it only to make objects (or animations earlier) but for my house, I’ll do it directly on UE4, it’s easier and I started yesterday 
Thanks for the reply, it’s appreciated