Commercial 
A double-cylinder deadbolt is the type that requires a key to lock it and unlock it from both sides of the door. It doesn’t have a thumbturn like a single-cylinder deadbolt. Once every so often we see a story in the news about a woman escaping decades of captivity in the home of some pervert who didn’t have any friends in high school, usually in upstate New York or western Pennsylvania. I would imagine that every one of the dwellings involved in those stories is outfitted with double-cylinder deadbolts on all the doors. For reasons wholly unrelated to child abduction, I hate to see these locks installed in homes where small children live.
A customer in Sammamish called me the other day to have me install one on his front door. His neighbor had just been burglarized. The intruder broke the window next to the single-cylinder deadbolt, reached his arm in, turned the bolt with his hand, and helped himself to the flat-screen television. So it’s not only perverts who install these deadbolts. Folks who like their flat-screen TVs also use them. I asked him if there were any kids in the house and then declined to do the job.
Double-cylinder deadbolts are illegal in Washington State, which requires that builders and contractors adhere to the International Residential Code. Section R311.4.4 states:
“All egress doors shall be readily openable from the side from which egress is to be made without the use of a key or special knowledge or effort.”
I didn’t suspect this client of being a depraved and disgusting lunatic. Rather, I was concerned about his two young children in the event of a fire. If the house was filled with smoke and flames and the door was locked with a key, it could pose a very significant problem to anyone inside—I dare say a much larger one than the loss of a flat-screen television.
I did throw out the idea of calling some window installers to inquire into putting security film over the windows flanking his front door, which would prevent the glass from shattering if struck. This is not something that I would choose to bother with, but he wanted to be proactive in the wake of this recent criminal activity in his quiet neighborhood. I also suggested putting a dog bone on the front porch and an alarm system sticker in the window. These are small but potentially effective deterrents that might make a burglar skip past a house and move on to the next.
Lastly, I directed him to the website of the National Crime Prevention Council, which publishes a helpful home security checklist. It’s a worthwhile document for any new homeowner to look over. Unsurprisingly, none of the items on the list prioritize crime prevention over fire safety, and neither do I.
www.ncpc.org/cms-upload/ncpc/File/homechk2.pdf