Need to Destroy Walls

I really need the ability to destroy walls on structures that I am designing.
I know i can use the undo button but it doesn’t always work. for example if i get attacked, deal with that then go back to my construction the undo button wont work. Or if I’m close to done with my build and decide i want one wall placed differently and have to undo most if not all of my work for one wall. it’s really frustrating and discouraging to have to destroy an entire building because you simply cannot remove one wall. I really hope this gets fixed soon,