I recently got an irate letter from an outspoken Peak Oil commentator who often stresses "community agriculture" and "sustainable development." He castigated me for "advocating a fortress mentality..." and "encouraging gun-buying..." I think that he meant those as insults, but I took them as compliments.
I am indeed an advocate of the fortress mentality, and fortress architecture. The two go hand-in-hand. As I pointed out in my book "How to Survive the End of the World as We Know It", modern American architecture with flimsy doors and large expanses of windows is just a 70 year aberration from a global norm that dates back many centuries. The real tradition in architecture outside of the tropics has always been to build homes with small windows, very stout doors, and lots of mass in the walls to absorb projectile impacts and to delay entry by evil-doers. Since 1945 we've been blessed to live a country that is relatively safe and peaceful. But don't expect that to last forever. Plan and build, accordingly.
Just look at the long history of the mote-and-bailey and castle in Europe and Fujian Tulou (Hakka) in China. Or look at the stout walls that are still the norm in Afghanistan and Pakistan. And consider the HESCO bastions that are almost always used by the U.S. military when deployed in any of the world's hot spots. I've said it before, and I'll say it again: There is no substitute for mass. Mass stops bullets. Mass stops gamma radiation. Mass stops (or at least slows down) bad guys from entering a home and depriving its residents of life and property. Sandbags are cheap, so buy plenty of them. When planning your retreat house, think: medieval castle.
The fortress mentality necessitates adopting fortress architecture. Whether you turn yourself into a moving fortress (with body armor), or you decide to design fortress features into your next home, I recommend that you prepare for as many different threats as possible. If you cannot afford to build your house like a fortress, or if that would "stick out" where you now live, then at least add a combination vault/shelter basement room to your house. (Either via new construction, or by remodeling.) Several SurvivalBlog advertisers can supply the know-how and crucial components for such a project such as inward-opening vault doors, blast valves, and HEPA filters. These companies include: Hardened Structures, Safecastle, and Ready Made Resources.
The bottom line is that in the event of societal collapse, looters will prey upon those who are obviously weak and defenseless. Unless they are suicidal, looters will consciously pass by any well-defended retreats. Why would they go up against an Alpenréduit when they could instead go pick on some defenseless granny living in a veritable glass box, a mile down the road? Why would they risk getting ventilated by a group of well-armed Rawlesians who are standing behind ballistic protection--especially while living in a world without readily-available medical care?
Planning ahead for bad times isn't paranoia. It is prudence. An integrated national defense should start with every hearth and home, and proceed systematically all the way to national borders. This is the true and righteous fortress mentality. The Swiss call this an "intellectual defense of the homeland" (Geistige Landesverteidigung). Their well-armed citizenry and their extensive system of réduits (many of them very well-hidden) have kept them free and essentially independent for 720 years. We should learn a lesson from that.