This is a conglomerate of several features that I would like to see implemented in order to facilitate housing building.

• Implement a global coordinate for the entire instance and a possibility to make the axes of each item or combounds parallel to that global coordinate system. This is important for precise positioning relative to each other, essential when you do construction with walls, doors, or any other sort.
  
• Implement a featore that allows exact stacking of two identical items. That is their axes are perfectly parallel and both origins of their respective individual coordinate system coincide. This will help precise constructions of combounds.
  
• Implement a way to mark a flat surface of an item and make it snap to another marked flat surface.
  
• Implement the possibility to make symmetric planes and/or axes of two items coincide.
  
• Allow copying of combounds, see thread: https://forums.elderscrollsonline.com/en/discussion/667363/suggestion-implement-copy-function-of-bound-furniture-groups#latest

EDIT: I know that some of these features are available by addons. But this should not be linked to an addon but be part of the basic housing features.