It is, and I am fully aware of the pitfalls. It was how I met my death in my world, actually. Locked inside the building when the bomb detonated, only able to save my friends. If I could find a way to correct that, perhaps it would be a better option.
I do understand, and I will try to see if I can come up with a way to get around the lockdown situation, to allow more flexibility. But I do think the safe houses are an option. Somewhere that only the residents would be aware of. Perhaps that would be a better option, but we would need a fail-safe plan to ensure the residents could get to the safe houses.