What is the weight of the bulletproof cockpit doors of a Boeing 747 built prior to 9/11? Do the doors weigh the same for later models, like the Boeing 747-8 specifically? How many fewer passengers do they have to carry in light of the added weight?
The FAA also assumed that the average safety door system adds 100 pounds to a large airplane. This additional weight would have minimal impacts on weight and distance limitations.
For a large airplane, like say the 747, it seems the weight addition is around 100 lb (including the other safety features such as the surveillance). As for the exact weight before/after, this information is not readily available as the doors are not sold to the public. But feel free to get in touch with Boeing if it's for research/educational purposes and such.