[markem]

Depends on what means by "safe" or "secure". Hinges on the outside? No indication where the house vents air or if there is a motor generator to prevent the owner being trapped inside. Doubt that the movable concrete is heavily reinforced, so vibration issues and longevity (i.e., fit and cracking) are a concern.

Interesting concept, but loads of practical concerns. Personally, the converted silo houses seem more secure to me.