Все, что осталось после бомбы, например.

Well...
"The building shell consists of the roof, floor, walls, windows and doors—everything that separates the inside of your building from the outside."
"Outer structure of a building."

это ни остов здания, ни "Все, что осталось после бомбы"

She didn’t write “building shell,” she wrote “shell of a building,” which I understand, without context, to be an idiom using shell: “During WW2, my family evacuated to Spain. A year later they returned to Germany. However, their town had been razed and instead of their home, they found a shell of a building.” -or- “The cancer had reduced him to a shell of his former, athletic self to the point that he was unrecognizable.”

OK, I though it was the same

😉

“After my divorce, I didn’t recognize myself anymore when I looked in the mirror. 20 of abuse had reduced me to a quivering wreck. I decided to find a therapist to help me pick up the pieces of my shell of a life and regain my identity.”