I spent a few years working at a complex that had pretty good security for its buildings. No, it wasn't a jail or anything like that, just a collection of privately owned buildings inside a perimeter. The company which owned the complex did a really good job on the security. Seeing a well secured commercial building makes you realize just how flimsy and unsafe the average single family dwelling is.
A few things I like from these commercial buildings that I would like to see implemented in a single family dwelling are.
Extra-wide, all metal door frames with steel reinforced wooden doors - no fiber glass/plastic (most residential interior and exterior doors). Heavy duty, hook style door knobs with each door having it's own deadbolt extending into the metal door frame with a keyed lock for the bolt. The doors would basically be a solid wood door with a metal sheets on either side with a welded exoskeleton around the door. These look like normal doors (the ones I have seen). Your fire department will be able to get in these doors - bad guys won't, not without a team of guys and specialized equipment. This is for all doors, interior and exterior.
Also, all exterior doors have electronic, proximity locks. Anyone who has worked in an office knows about these. Basically a key fob very quickly unlocks the door for you. The door is always locked, but entry and exit takes a second or two with the fob, much, much faster than trying to fumble with keys and get the door open. If you had to say, flee an attacker and enter your home quickly this would be your ticket. Plus, since the door is always locked as soon as the door swings shut it's secured, no interior locks to fumble with. All these doors can be manually unlocked with a standard key as well.
It was already mentioned but I'll mention it again. Metal security mesh for the inside of walls, secured to the framing. These metal meshes are placed at the center of the framing behind any electrical or plumbing for the rooms. You wouldn't need these for all the walls but the bedrooms are a good idea and all exterior walls, assuming you don't have real brick or concrete block construction. Chances are if you live in the SE and have a home built after 1990 you have concrete block at least for the first floor, with wood framing for the second floor, if you have one.
The next item might sound like overkill to some but I think it's a good idea. Half-height, wrought iron bars for all first floor windows. Yes, I said it, put bars on your windows. Here's how to make them look decorative and nice and NOT like trash. Paint them the color of your shudders or house trim, make sure you use half-height bars, full height aren't needed - no one is going to climb over them, if they try they will get holes poked in them. Also, put flower boxes on the outside of them to hide the base. Also, put shrubs outside these windows which reach slightly above the base of the bars. People won't notice them and the window will be secured and look nice.
Cameras - you need a camera system, but there are so many ideas on this, it needs its own thread.
Lastly is a good outside lighting system which illuminates all the areas around the house, specifically entry doors and first floor windows. Yes, you can effectively light the exterior of your home without flooding your neighbors windows with light. I've done it, it requires using overhangs to channel the light downward against the door/window/wall/yard and not out into the road or at a neighbors house. I have my entire exterior lit attached to two switches, one in my kitchen and one in my bedroom which activates all the lights, either switch.
Hope that helps!
j/k) I'd have probably built one too. They lived within the fallout range of multiple nuke targets. Can't blame a man for wanting to protect his family the best way he could given the times. Interestingly the grandparents who built the bunker are also hardcore anti-gun. No ammo stashes in that bunker.
