Interior Build Camera v1.0.0.0

Decorate the inside of your buildings!
In the base game, the construction camera gets pushed up and out the moment it touches a roof or a wall — so you can never actually see inside a building, let alone furnish it. Interior Build Camera removes that limit with a single hotkey: flip it on and the camera glides straight through walls and roofs and drops all the way down to floor level, giving you a true eye-level view of any room while you build.

How to use:
Enter construction mode as usual.
Press LEFT CTRL + I. A short "Interior camera: ON" message confirms the toggle.
Move, zoom and tilt into any building — the camera now passes through walls and roofs and can sink to just above the floor.
Decorate and place objects exactly like you would anywhere else.
Press LEFT CTRL + I again to instantly get the normal construction camera back. 

Features:
One-key toggle, no menus needed — the current state is also shown in the input help (F1)
Camera moves freely through walls and roofs while the toggle is on
Drops to near floor level for eye-level interior shots
Never falls below the terrain, so you can't end up under the map
Works in both construction mode and landscaping mode
Key freely rebindable under Options > Controls ("Toggle interior build camera") 

Good to know:
Camera-only mod: placement rules, savegames and multiplayer data are completely untouched
If an object refuses to be placed indoors, that is the game's normal placement collision at work — not this mod
Safe to add or remove at any time with no effect on your savegame