Two Letters Re: Home Invasion Robbery Countermeasures–Your Mindset and Architecture

I have not yet seen mention of “air locks” as a security layer for entry doors. Many years ago I managed a software project that included doing installs at armored car companies. The visitor entrance had you go in one set of doors to a small holding room. Here a security receptionist behind thick glass and gun ports could identify you and hold you until they were ready. Only then could you enter a second set of doors into the main facility, which would be analogous to an inner courtyard in a residential estate (i.e., an open area surrounded by secured offices and security stations with more gun ports). There was no way possible for someone to just barge in through the public doors into the private work areas.

I have always been intrigued with this “air lock” concept for security in a home design. The security screen door might be a micro version of this concept. The walled yard with a security gate is closer to the full concept. Even with those ideas in place, I would still like to have a secure foyer in which visitors could enter and be fully observed and communicated with but still protected by a second beefy security door.

Then if the secure foyer opened into a sort of atrium, you can interior rooms overlooking the foyer have bullet resistance windows and discreet firing ports. It doesn’t seems like it would take too much to design an attractive home with many substantial security layers:

– Walled yard with remote controlled security gate, intercom and security camera
– “Air lock” foyer with observation windows and discrete firing ports and remote controlled secure exterior and interior entry doors
– Interior atrium or courtyard with interior rooms having overlooking bullet-proof windows and firing ports(maybe with decorative sliding covers?)
– Gate or steel door to block off bedrooms from living areas at night
– Safe room inside the bedroom area for final retreat location
– Escape tunnel or hatch from safe room to outside into a camouflaged exit point (bushes, shed, etc.)

Are you aware of any traditional architecture styles that incorporate many of these security layers? For instance, I learned in a cultural training class that in Italy new acquaintances are never invited to a private home for visiting. You always arrange to meet in public until you are well known and then only come over at an invited time, never to just “drop by”. You would never invite a bunch of people over and e-mail them a map to your house to just show up for a party. Only family and close friends are invited into one’s house. Also, the houses tend to have outside gates and entry doors away from the living areas so unless someone expects you, you will never get close enough for them to even know you are there wanting to come in. Sort of a cultural OPSEC. – The NW Pilgrim

JWR Replies: Thanks for mentioning those design approaches. For several years, I worked for defense contractors that had secure (SCIF) facilities. This gave me some first-hand experience. For any readers interested in detailed specifications, do a web search on the phrase “Man Trap AND Entrance”. You’ll find articles like this one. One proviso: If you utilize a man trap door system to hold a miscreant, then you must immediately declare “you are under citizen’s arrest” and summon the police or sheriff’s deputies. To do anything else–or otherwise delay–could be the grounds for a civil suit or criminal prosecution.


Hi Jim,
The after market security films [mentioned by another reader] may not be useful as advertised. The issue is that the laminate film is not secured sufficiently to the window frame. An intruder can knock out the glass plane at the edges to gain entry. The security laminate films are more of a safety measure against severe weather by preventing glass shard injury.

Most of the security laminates are secured to a window frame with a small bead of silicone, but this offers little resistance to a blow by a crow bar that can deliver thousands of pounds of pressure per square inch. A intruder could knock out a corner of a window and reach inside to open the lock.

Some vendors use a thick PVC frame that is bonded to the window using an adhesive. However this is still likely not strong enough to hold back a determined intruder for very long. The film lamination may provide between 30 to 50 sec of delay.

If you watch this video of a test with a product using the PVC frame it takes just a few blows to cause the PVC frame to partially blow out. I believe a determined intruder can knock the window enough to get his hand to reach the lock in a matter of seconds.

I believe the real solution is to have the security laminates installed at the factory when the windows are manufactured so that laminate security film is installed into the window frame. I would also like to note that these security laminate films do not offer protection against bullets.