First of all, let us talk about what's happening globally.
This is a nice little site that defines and deals with all sorts of resilience issues in cities around the world. it's well worth a look.
My city, Tel Aviv, has many plans for many types of crisis. First and foremost there is the issue of earthquake protection. many claim a big on is coming and so Tel Aviv began to prepare.
They thought of a nice little solution to the problem of reinforcing old buildings, by allowing them to expand their balcony in return for strengthening the building itself. Many contractors are now offering building a plan where they expand the buildings both up and to the sides for free. the building gets reinforced, the residents get a new balcony for free and the contractor gets to sell the apartments on the new floors. Win win.
Another issue is building upwards. Tel Aviv has long run out of room to expand and so all new buildings are at least 9 floors high. many are above 20 and office building being built today are above 40. I think this is an excellent use of space and will allow more people to do more on less land, thus lowering transportation costs as well.