Costs of building a gun vault?

[resdep]

Great thread and great ideas. I added on to the house about 8 years ago and that included expanding the basement. I had a contractor pour the ceiling on part of the added basement, yes I had the ceiling figured by an engineer, and I used heavy steel doors. Maybe not as secure as a safe door but the doors are hidden. So I guess if my local swat team wanted in they could blow them. One of my shooting buddies was on a team a lot years and he didn't think they could break them in with the equipment they have. I ended up with a 12 x 16 safe room with 8" steel reinforced walls and ceiling w/ventilation and a hidden exit. I think the final cost ended up adding about $6000 to the cost of the addition.