July 4, 2017
by Michelle Witherby and Paul Witherby
Glass doors and walls in commercial spaces have transformed how people work, play, shop, and socialize. Glass provides a clean, crisp, contemporary look that can allow for natural daylight to flow from one interior space to the next. Study after study, including some by the National Renewable Energy Laboratory (NREL) (for more, see “A Literature Review of the Effects of Natural Light on Building Occupants,” by L. Edwards and P. Torcellini from the National Renewable Energy Laboratory [NREL]) and the U.S. Green Building Council (USGBC) (USGBC’s October 2014 study, “Applying Research to Boost Productivity in Your Office” by Robert Best), show how natural light can improve cognitive function, mood, and productivity. Glass brings many benefits, but designers need to carefully consider how to make spaces accessible and keep a watchful eye on requirements set forth by the Americans with Disabilities Act (ADA) of 1992.
According to adata.org, “People with disabilities are the largest and fastest-growing minority in the U.S. They control $1 trillion in total annual income. They have friends, family members, and business colleagues who accompany them to events and outings. And they use businesses and facilities that are accessible to them.”
Everyone deserves ease of access to government and commercial buildings. That is why related specifications and laws are now incorporated into building codes at federal, state, and local levels.
ADA is a U.S. labor law. Similar to the Civil Rights Act of 1964, which made discrimination based on race, religion, sex, and national origin illegal, ADA prohibits discrimination based on disability. It also goes a step further, requiring employees with disabilities are provided accessibility and reasonable accommodations. Applying to federal, state, and local government agencies, as well as private businesses open to the public, the laws went into effect in 1992. Any building built before this date may need upgrades to be compliant. All buildings constructed or renovated after 1992 must comply.
Interior door and hardware compliance
Federal ADA compliance codes and requirements are a standard for architects and designers to follow during construction or renovation. To help design professionals follow the law, there are multiple resources for reference. Some issues specific to the 2010 ADA are also addressed by International Code Council (ICC) A117.1, Accessible and Usable Buildings and Facilities. This standard is referenced by the International Building Code (IBC), International Fire Code (IFC), and National Fire Protection Association (NFPA) 101, Life Safety Code, for doors on an accessible route. (Read The Construction Specifier article, “Understanding New Accessibility Requirements for Doors” by Lori Greene, AHC/CDC, CCPR, FDAI.)
Briefly, here are the most common ADA compliance guidelines to follow.
Door clearance width
Whether a door opens and closes by swinging, sliding, or folding, it must allow a minimum 810 mm (32 in.) of clear width for accessibility. This distance is measured from the face of the door to the opposite doorstop. In addition, the lower 250 mm (10 in.) of the full width of the door must be free of any projections that would impede the use of wheelchairs and other mobility devices. Any spaces due to kick plates must be capped.
Door hardware must not require more than 22 N (5 lb) of force to operate and must be operable with one hand without the need for tight grasping, pinching, or turning of the wrist. By this requirement, round doorknobs are not accessible. The preferred handle is a lever or pull-bar style.
Door clearance threshold
The floor underneath the door is called the threshold, and it cannot be more than 13 mm (½ in.) higher or lower than the flooring or pathway leading to and from the door. Allowances are made for 19-mm (¾-in.) height, provided a beveled slope is placed on either side of the threshold to ensure a smooth transition through the doorframe.
Maneuvering space required
Whether the door is hinged and opens inward/outward or slides or folds to the side, there must be clear space to accommodate wheelchairs and other mobility devices prior to passing through the doors as they are opening and closing. In other words, a person in a wheelchair must be able to approach the door, turn the handle, and freely enter or exit through the door.
Door closing speeds can vary by door type and location. Interior doors with closers should take a minimum of five seconds to move from the open position at 90 degrees to 12 degrees from the latch. Doors with spring hinges need at least 1.5 seconds to close from a 70-degree open position. Closing times for automatic doors vary depending on the type of door (i.e. swinging, sliding, or folding), as well as the dimensions and weight of the door. American National Standards Institute (ANSI) A156.10, Power-operated Pedestrian Doors, covers the requirements for ‘full-power’ automatic doors, while ANSI A156.19, Power-assist and Low-energy Power-operated Doors, addresses ‘low-energy’ or ‘power-assisted’ doors. (Further reading available here.)
How ADA compliance has an effect on manufacturers’ design
Just as there are requirements for door size, width, and placement, there are special requirements for door pull handles. This hardware needs to be within easy reach of someone in a wheelchair or other mobility device. There must be sufficient space from the door surface to allow for the hand to grip the handle. Again, to avoid tight grasping, pinching, or turning of the wrist, doorknobs should be avoided when it comes to ADA compliance. Three approved ladder pull handle systems are:
Ladder pull with lever turn
The ladder pull with lever-turn actuator replaces the standard thumb-turn, rotates 180 degrees without a push-button actuator, and must adhere to ADA’s operational guidelines. The lever pull handle must be designed and installed no more than 1220 mm (48 in.) above the finished floor (AFF). The margin of height is 965 mm (38 in.) minimum to 1220 mm maximum AFF, or 915 to 1170 mm (36 to 46 in.) AFF in California.
As the most recent addition to ADA-compliant door hardware, the staggered pull offers a floor-locking option instead of top-locking while meeting accessibility regulations. It requires a compliance of 250-mm (10-in.) clearance AFF on the corridor side while allowing a full-length pull on the office side. The staggered pull design is available in both locking and non-locking ladder styles.
The top- or ceiling-locking ladder pull is the most frequently used door handle. Architects and designers make this selection based on ease of use and aesthetics, since this style can be designed in a variety of shapes and finishes. The ladder pull needs to be installed a clear distance of 65 mm (2 ½ in.) from the glass surface to the inside of the pull surface to allow for ease of hand movement. A bottom- or floor-locking ladder pull can also be used, as long as it provides a 250-mm clearance from the bottom of the door.
Other considerations for ADA-compliant pulls include rules for sliding door design, which require no more than 22 N (5 lb) of force to operate and have exceptions for spaces smaller than 30 m2 (300 sf).
When codes collide
In addition to federal law, accessibility building codes can vary at state and local levels, leaving builders to consider—or, more accurately, ‘muddle through’—the different or additional accessibility requirements. Subject to individual interpretation, such gray areas can result in unfortunate, costly mistakes.
California, for example, is a state with its own unique set of regulations. In this state, top-locking, lever-actuated ladder pulls comprise the only approved design solution for ADA conditions. Additionally, the range of dimension of the center of the locking post AFF is 915 to 1170 mm (36 to 46 in.) specifically, whereas in all other states, this is 965 to 1220 mm (38 to 48 in.). Currently, no other states seem to be following its lead.
Enforcing compliance codes
Generally speaking, it has been a challenge for various industries to get a clear understanding of ADA accessibility requirements. As with most regulations, enforcement is up to interpretation as well as ongoing changes to the act by region. When designing pull handles, it is important to consider both national and state requirements.
Responsibility for compliance falls on many shoulders, and is therefore often a gray area. Assumptions may be made that the manufacturer considers ADA when designing, or that the architect or designer has a strong grasp of its requirements. When it comes down to final approval, doors and their hardware are inspected by local building officials and construction inspectors who are well-versed in federal and local building codes. They can inspect buildings at any time during the final installation and determine whether the building receives a certificate of occupancy (CO). Of course, their individual interpretation can either accept or decline installed hardware.
Shape as a common error
A thumb-turn actuator is one of the most common errors architects and designers make when specifying handles. This actuator requires a two-point dual action, such as press and rotate, to operate. A lever-pull handle requires only a one-point lever actuator to operate and is a compliant solution.
Avoiding mistakes can be as simple as reviewing ADA guidelines and doing some pre-planning before construction begins or products are purchased for installation. It is also crucial to check with suppliers to see which ones align with ADA codes and their impact on the project. These steps can save the cost of redoing a project.
Understanding and working within the guidelines of accessibility codes benefits owners, architects, and designers, especially economically. If the correct architectural hardware is specified from the beginning, this provides peace of mind and confidence that approved, proper design solutions are being selected and installed. This eliminates expensive change orders and costly error replacements, per site inspectors and compliance regulators.
Since the act went into effect, accessibility into and within any building for everyone is the standard—whether the project is a retrofit or new construction. There are regularly updated building codes and requirements to follow at federal, state, and local levels. Sometimes, these are clear-cut, but other times, they may be conflicting.
The best way to handle them and ensure compliance is to work with manufacturers experienced in accessibility code compliance. Architects and designers need to check and re-check their interior glass doors and hardware before specifying products and installing them. A little pre-planning in the beginning ensures a job done right at final inspection.
Michelle Witherby, COO, together with sibling Paul Witherby, founded Miami based T-Concepts Solutions (TCS) in 2001, and today, the company is one of the fastest-growing global suppliers of architectural hardware for glass doors, serving both residential and commercial markets. Witherby leads the operations, marketing, and international sales and partnerships for the company. Her passion for modern design and specialty architectural products, and their influence specifically on mixed-use and hospitality construction helped to segue TCS from an industrial design house into the world of architecture and design. Witherby studied international business at the University of Georgia. She recently co-authored the ADA Compliance Guide, available for download at t-concepts.com/ada-compliance-guide. Witherby can be reached via e-mail at firstname.lastname@example.org.
Paul Witherby, CEO, is an expert in industrial machine design and fabrication. An early innovation in his career was designing sliding door systems for space-saving efficiency on factory production floors. The technology was soon re-engineered to be used for many multifamily and hospitality projects around the United States. From there, Witherby helped TCS become one of the first companies in the country to integrate form, function, and style with moveable wall systems, space partitions, light-sharing designs, sliding door hardware, and telescoping glass office fronts. He holds a mechanical engineering degree from North Carolina State University. Witherby can be reached via e-mail
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