Are the Deadbolts on Your Home Code-Compliant?

If you take a trip to the hardware store or go online to purchase a deadbolt for your home, you will find a wide array of products.  However, most deadbolts can be divided into two categories:  Single cylinder and double cylinder.

            A single cylinder deadbolt is one where there is a keyed cylinder on the secured side (outside) of the door and a thumbturn on the egress side (inside) of a door.  An authorized person may enter by using a key and then secure themselves within the space by flipping the lock's thumbturn.  Any person may egress by rotating the thumbturn and opening the door. 

Schlage B60N single cylinder deadbolt, view from egress side of door.  Notice the thumbturn

             A double cylinder deadbolt is one where there are keyed cylinders on both sides of a door controlling a single bolt.  If the door is locked, one must use a key to open it regardless of which side of the door they are on.  Therefore, anyone without the correct key cannot exit through a door secured by one of these locks.  This creates a serious life-safety hazard.

 

Schlage B62N double cylinder deadbolt, view from egress side of door.  Notice the key

            The Residential Code of New York State (RCNYS), 2010 Edition sets forth the egress requirements for all residential structures that the code applies to (most one or two-family dwellings).  Specifically, the code requires that “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” (quoted from RCNYS R311.4.4).  Therefore, double cylinder deadbolts violate this requirement when used on an egress door.  While the local Authority Having Jurisdiction (AHJ) could theoretically override this requirement, this would be highly unlikely due to the potential life safety hazard this would present.

            For instance, if there is a fire, or if the Carbon Monoxide alarm within a residence starts sounding, immediate and unobstructed egress is critical in preserving the lives of all occupants.  If instead, the occupants are tasked with finding a key, or if the key holder becomes trapped or incapacitated then all the occupants could be killed very quickly.
            The only instance where a double-cylinder deadbolt would likely be permitted, would be on a door between two separate areas, each of which has it's own unique egress door.  For example, if a single-family structure has been converted to house two separate tenants, a door separating the two occupancies could be permitted to have a double-cylinder deadbolt, as this would not impede egress from either occupancy.
             Some homeowners may wish to have a double cylinder deadbolt on a door with a window in it for fear that if they used a single-cylinder deadbolt a burglar could smash the glass, flip the thumbturn and gain entry.  However, there are other alternatives that do not compromise life safety, such as protective window covering or an alarm system that utilizes door position switches and Passive Infrared (PIR) sensors.

            On a personal note, a friend of mine used to rent an apartment from a landlord who had gone so far as to secure each tenant’s bedroom door with a hasp and padlock!  This means that anyone could lock a tenant in their room and if a fire were to start, the tenant would be trapped.  This is probably the grossest violation I have seen to date of this requirement.  Also, the landlord used Master Lock airline-luggage-sized padlocks and left the hasp screws exposed, so anyone could gain entry either by backing out the screws with a Phillips screwdriver or giving the padlock a good swift hit with a hammer!

            In conclusion, homeowners should refrain from using double cylinder deadbolts on any entrance or egress doors and instead go with the single cylinder alternative.  By eliminating the double cylinder deadbolt entirely, the homeowner also eliminates the legal liability and inherent hazard that comes with it.

DISCLAIMER:  This post is not intended in any way to offer legal advice.  For advice on what hardware is allowed or prohibited in a given jurisdiction, please check the building codes in your area and contact your Authority Having Jurisdiction (AHJ)