There are two possible solutions depending on the situation:
Make the house a skeletal mesh and animate the door opening in 3ds Max.
Split the door into a separate object and use blueprints to open it.
If you are planning on entering the house during gameplay you will have an issue with the collision model applied. You can either remove the collisions and use blocking volumes or create a simplified collision model in 3ds Max using UCX.
IMO, It is easier to split buildings into multiple pieces and reassemble them into a blueprint in UE. This solves the overlapping Lightmap UV issue with complex meshes and makes collision generation easier.