Archive for December, 2009

Access-Controlled Egress Doors

December 22nd, 2009

Nowadays security is a top priority for commercial properties due to terrorism, corporate espionage and threats to personal safety.  In the design phase of new buildings or renovations to tenant spaces, designers must take care that security measures meet the requirements of the building code.  I will talk specifically about Access-controlled egress doors (section 1008.1.3.4 of IBC 2006).

This section talks not only about entrance doors to a building, but any doors which are part of a means of egress.   In other words, if one has to go through a door to get out of the building, the following requirements must be met:

1)    A sensor must be installed on the egress side which detects an occupant approaching.  The door(s) must open either by a signal from or loss of power to the sensor.

2)    Loss of power to the access control system unlocks the door.

3)    Manual unlocking device must be placed on the egress side of the door.

4)    Activation of the building fire alarm (if provided) system shall unlock doors.

5)    Activation of building sprinkler or fire detection system (if provided) shall unlock doors.

6)    Entrance doors (not to be confused with entrance doors in a means of egress) in Groups A, B, E or M shall not be secured from the egress side when the building is opened to the general public.

We will look at three scenarios where security requires controlled access to a space.  First, we will look at the CEO’s office (figure 1). Her office is on the 32nd floor of a high rise building.  Security concerns require entry to the reception area leading to her office is gained only by keycard access. Placing the sensor and manual unlocking device on the reception side of the doors will not allow access to the office by an unwanted occupant(unless they know how to set off the fire alarm/ detection system, sprinkler system or cut power to that part of the building).  This scenario can easily comply with code requirements.

Figure 1

Figure 1

In the next two scenarios, meeting code requirements will defeat the purpose of providing the access control.  First we will look at locked doors in an elevator lobby (figure 2). In a multi-tenant high-rise, it is normal for tenants to restrict entry to their floor.  Locking stair doors from the stair side is allowed under certain conditions.  The only other access to the floor would be from the elevators.  If access control is installed at the elevator lobby, 2 of the code requirements would defeat the purpose of the locking devise.  Since the stairs (means of egress) are on the other side of the door (the tenant space), the sensor and the manual unlocking device have to be located in the elevator lobby.  The person you are trying to keep out just has to walk up to the sensor or manual unlocking device to get in.

Figure 2

Figure 2

Finally, we’ll look at a floor of a high rise building which has two different tenants (figure 3).  In this design, each tenant space has one stairway.  Two means of egress are required for each space so installing locking devices on doors leading to the other stair would require the sensor and manual unlocking device on the egress side,  again defeating the purpose of the locks altogether.

Figure 3

Figure 3

The solution?  Forethought.  By the time this issue is brought to the forefront, rerouting egress paths is impossible. A lot of the time, the controlled entry devices are installed by the owners without the knowledge of the general contractor and sometimes after final inspections.  I was once involved in a project that received a variance from the local authority.  They were not required to install the sensor or manual unlocking device (both of which would have defeated the security measure).  They did have a non-required sprinkler system in the building.  They didn’t, however, use the exception for pull station requirements (because of the sprinkler system) and placed pull stations throughout the building accessible to the public.

NOTE: Section 1008.1.4.4 of the 2009 IBC, access-controlled egress doors remains the same as 2006 except Group I-2 is added to groups A, B, E, M, R-1 and R-2 where access control is allowed.