This post was published in the October 2016 issue of Doors & Hardware
Many of today’s architectural designs incorporate outdoor spaces such as balconies, terraces, and courtyards, allowing building occupants access to natural light and fresh air. Because these areas often have an egress path which leads through the building to the public way, it can be difficult to balance security needs with the egress requirements. The requirements discussed in this article apply to courtyards that are fully enclosed – often by the building on all 4 sides, and to balconies and terraces without stairs leading directly to grade.
Exterior spaces that don’t have direct access to the public way are typically required to meet the same egress requirements as an interior room. This ensures that a building occupant within a courtyard or on a terrace or balcony has a code-compliant means of egress – or more than one means of egress if required by the adopted code.
Some of the code considerations include:
- Operable Hardware – Egress doors are required by the model codes to be equipped with hardware that can be operated to release the latch(es) with no key, tool, special knowledge, or effort. This applies to egress doors serving an enclosed exterior space as well – a building occupant must be allowed free egress from the courtyard, terrace, or balcony directly to the public way or through the building and out to the public way. While it is often acceptable to lock the doors to prevent access to the exterior space, egress must not be obstructed.
- Panic Hardware – For Assembly and Educational occupancies, panic hardware is required by the International Building Code (IBC) for doors which lock or latch serving an area with an occupant load of 50 people or more. NFPA 101 – The Life Safety Code requires panic hardware for these doors when the occupant load is 100 people or more. No other security device which would prevent egress may be installed on doors equipped with panic hardware.
- Door Swing – When an egress door is serving an occupant load of 50 people or more, it is typically required to swing in the direction of egress. For a large enclosed courtyard or terrace, the doors would swing from the enclosed exterior space into the building. The occupant load is based upon the area of the occupiable space divided by an occupant load factor which varies depending on how the space is used. These factors can be found in the model codes.
- Number of Exits – If the occupant load of an area is 49 people or less, the model codes require only one exit from the space for most occupancy types. But some occupancies require a second exit even when the occupant load is less than 50 people. Large enclosed areas may require 3 or more exits – the IBC requires 3 exits when the occupant load is 501-1,000 people, and 4 exits when the occupant load is greater than 1,000. Travel distance and common path of travel limitations can also affect the required number of exits and their locations.
- Opening Width – For most locations, the minimum clear opening width for an egress door (and at least one leaf of a pair) is 32 inches. This width is measured from the face of the door open to 90 degrees, to the stop on the strike jamb of the frame, or to the vertical mullion, or to the other leaf of a pair in the closed position. The minimum clear width can also be affected by the required egress width, which is the amount of opening width needed in order to accommodate the number of occupants within the space.
- Accessibility – Doors serving occupiable exterior spaces must typically meet the accessibility standards, including the use of operable hardware to release the latch without tight grasping, tight pinching, or twisting of the wrist. The requirements for maximum threshold height, maximum force to operate the door, and a 10-inch flush surface on the bottom push-side face of manual doors also apply in most locations.
- Special Locking Arrangements – The model codes include requirements for delayed egress locks and other types of electrically or electromagnetically locked doors. These applications may be used on doors serving enclosed exterior spaces if all of the criteria are met. It’s important to note any limitations that are dependent on the occupancy type.
Given all of the requirements for free egress from enclosed exterior spaces with an egress path leading through the interior of the building, there are obvious security conflicts. If it’s possible to access the exterior space by climbing over a low roof or gaining access to an exterior terrace, unauthorized entry to the building could be made through doors designed to provide a safe path of egress. If these concerns are raised early in the design process, there may be ways to limit access from the egress path to the balance of the building so that an unauthorized person entering through the exterior space would not have free access to the majority of the building.
In some cases, an Authority Having Jurisdiction (AHJ) may allow these requirements to be modified to address security concerns. Alternate methods may include fail safe electrified hardware which could be used to lock the exterior space in the direction of egress when the building is not occupied. This type of system could automatically unlock when the fire alarm is actuated, and a means of communication could be provided in the exterior space, to allow a building occupant to call for assistance. Because these alternate methods are not specifically addressed in the model codes, each situation would have to be reviewed and approved by the AHJ. Occupiable roof-top areas have similar requirements, and were covered in a previous Decoded article.