I don’t get involved with residential construction very often, but a local locksmith recently asked about the use of double-cylinder deadlocks on single family homes. His position is that he will not install them, but he was looking for a code reference to back him up.
When I checked the Massachusetts One and Two Family Dwelling Code, I found that double-cylinder deadlocks are prohibited. I found the same language in the 2009 edition of the International Residential Code (IRC).
Your local code might contain a different requirement, but here’s the paragraph from the 2009 IRC:
R311.2 Egress door. At least one egress door shall be provided for each dwelling unit. The egress door shall be side-hinged, and shall provide a minimum clear width of 32 inches (813 mm) when measured between the face of the door and the stop, with the door open 90 degrees (1.57 rad). The minimum clear height of the door opening shall not be less than 78 inches (1981 mm) in height measured from the top of the threshold to the bottom of the stop. Other doors shall not be required to comply with these minimum dimensions. Egress doors shall be readily openable from inside the dwelling without the use of a key or special knowledge or effort.
Here’s a tragic news report involving double cylinder deadlocks.
November 30th, 2010 8:43 am
I see you did not talk to the police
Some push the double cylinder locks
November 30th, 2010 9:08 am
Hi Charles -
No, I didn’t talk to the police (I avoid that if possible), but you bring up a good point – the struggle between security and life safety. Hardware consultants get stuck in the middle all the time when we’re asked to specify/supply hardware that meets the security requirements but isn’t code-compliant. In my opinion, it’s our responsibility to point out these issues to the architect, owner, and the various consultants and to try to come up with a viable solution.
I spent 2 hours with a building inspector last week going over a very high security building I’m working on. We went through the egress plans and the operation of the hardware, and she confirmed which doors would require a variance. I’m not suggesting that every homeowner should ask for a variance for their double-cylinder lock, just that we need to maintain the balance between life safety and security, and that the code officials (you guys) can be allies to the hardware industry (us) in this endeavor.
- Lori
November 30th, 2010 7:27 pm
My side door has one and my main entry has cylinder outside x blank plate inside so the house can only have both deadlocks thrown when I’m not in it.
December 2nd, 2010 1:17 pm
Mr. Caron,
This is an interesting idea to have a blank plate, but what do you do at night to lock and secure you main entry door? If you are asleep at night, and wanted a deadbolt on your main entry door to be thrown for the additional security it provides a homeowner (which is typically why a deadbolt is on the door in the first place) how would your application work (the only way I can make it work in my head is to then have an integrated deadbolt lock, which, I would think, would defeat the purpose of having the deadbolt with a blank plate).
March 14th, 2011 10:49 am
2006 IRC – R311.4.4 Type of lock or latch. 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.
2009 IRC – R311.2 Egress door. At least one egress door shall be provided
for each dwelling unit. The egress door shall be side-hinged,
and shall provide a minimum clear width of 32 inches (813
mm) when measured between the face of the door and the stop,
with the door open 90 degrees (1.57 rad). The minimum clear
height of the door opening shall not be less than 78 inches
(1981 mm) in height measured from the top of the threshold to
the bottom of the stop. Other doors shall not be required to
comply with these minimum dimensions. Egress doors shall be
readily openable from inside the dwelling without the use of a
key or special knowledge or effort.
March 14th, 2011 3:22 pm
Thanks Roger!
May 1st, 2012 8:11 pm
I know this is an old post, but I have a question. The paragraphs sited all say “at least one egress door shall be provided”. So, assume a home with multiple doors, one of which has no glass in it or near it. Can the homeowner put a single cylinder lock on it and declare it the official egress door, and then put double cylinder locks on the doors with glass?