"Lighting (and light discipline) and trained dogs are a whole lot more effective than trip wires and gimmicks, and easier to pull off. You don't even need big dogs. In a lot of ways, the jumpy, barky ankle biters are more effective alert dogs. They're not going to do much in the way of deterrence in case you gotta deal with something smarter than a zombie, but they don't require a whole lot of food and water.

Of course, this is presuming that whatever causes zombies to be zombies doesn't also affect dogs (like it does in "I am Legend" 2007)."

"The best defense is being unnoticed. Anything that makes noise or light could draw attention to your location (unless you are somewhere noiseproof or soundproof, like a sound studio or panic room or room with blacked out windows). If nobody knows you're in a building you're better off locking the doors and staying away from the windows. If somebody has to break down a door or crash in a window to get to you it should be enough noise to alert you unless you're drunk or something. Especially if you put a bar on the door, nobody is getting to you quietly."