AAMA Seeks Code Modification for ADA Threshold HeightApril 27, 2012
On July 26, 2010, the 20th anniversary of the Americans with Disabilities Act (ADA), President Obama announced newly revised ADA regulations.
The regulations, entitled the 2010 ADA Standards for Accessible Design, went into effect March 15, 2012, for physical construction or alterations commencing on or after that date. Property owners across the country are now required to meet these expanded regulations for renovation or construction projects or risk ADA compliance lawsuits.
These changes, now promulgated in the I-codes, include threshold height issues of concern to Door Council members.
Before discussing the specific issues impacting our industry, it’s important to understand some terms included in the regulations.
- Title II of the ADA protects people with disabilities from discrimination on the basis of disability in services, programs and activities provided by state and local government entities. Title III prohibits discrimination on the basis of disability by places of public accommodation (businesses that are generally open to the public, such as restaurants, movie theaters, schools, recreational facilities and doctors’ offices).
- Residential Occupancy Group “R,” covers uses intended for sleeping purposes. It includes Group R-2, which identifiesoccupancies containing sleeping units or more than two permanently occupied dwelling units. Group R-3 encompasses one- and two-family dwellings or adult and child care facilities that provide accommodation for five or fewer persons of any age for less than 24 hours.
- Type B is a designation indicating a set of criteria for a number of building features, as defined in ICC/ANSI A117.1, Accessible and Usable Buildings and Facilities, Section 1003, which complieswith the design and construction requirements of the federal Fair Housing Act. Every apartment in R-2 occupancy buildings with more than four dwelling units are required to meet the requirements of Type Bunits.
The current issue concerning the threshold requirement is that the Department of Justice has issued a Fair Housing Act interpretation that requires doors to a deck or balcony from an apartment to meet the accessibility criteria for a Type B unit. That means that any such doorway must have a threshold no higher than 1/2 inch in new construction or 3/4 inch in existing or altered construction, and anything over 1/4 inch must be beveled at a 1:2 (50 percent) slope. Anything greater than 1/2 or 3/4 inch must employ a ramp.
This means thresholds higher than 1/2 or 3/4 inch above the interior floor level are not permitted, even though a step-down of up to 4 inches is permitted between the interior floor and the walking surface of the exterior deck or balcony.
This limitation on threshold height can have an impact on the system’s resistance to water penetration. In view of this, AAMA has submitted an International Building Code (IBC) change proposal that would permit the threshold height to be included within the permitted 4-inch step-down.
The IBC states the threshold requirements as follows:
1008.1.7 Thresholds.Thresholds at doorways shall not exceed 3/4 inch in height above the finished floor or landing for sliding doors serving dwelling units or 1/2 inch above the finished floor or landing for other doors. Raised thresholds and floor level changes greater than 1/4 inch at doorways shall be beveled with a slope not greater than one unit vertical in two units horizontal (50 percent slope).
This code includes an exception to the requirement. Notably a 7 3/4-inch step-down is permitted for exterior doors that are not part of the required means of egress and which are not serving defined “Accessible” units, Type A units or Type B units. This exception corresponds to Exception 3 to Section 1008.1.5, which permits residential exterior doors to have a step down of up to 7 3/4 inches from the interior spaces to an exterior landing, provided the door does not swing over the landing.
Exception 5 (at 1008.1.5) does allow exterior decks, balconies or patios that are part of Type B units to be up to 4 inches below the finished floor level of the adjacent interior space but no exception for the threshold of the doors between those spaces is provided.
The AAMA code change proposal (E60) seeks to add a second exception at IBC 1008.1.7:
In Type B units, where Exception 5 to Section 1008.1.5 permits a 4-inch (102 mm) elevation change at the door, the threshold height on the exterior side of the door shall not exceed 4 3/4 inches (120 mm) in height above the exterior deck, patio or balcony for sliding doors or 4 1/2 inches (114 mm) above the exterior deck, patio or balcony for other doors.
This proposal would permit the height of the threshold itself to exceed 1/2 or 3/4 inch in height, as long as the additional height is contained within the permitted 4-inch step down between the interior floor and the exterior surface.
AAMA’s rationale for the change is that the higher threshold is needed to prevent water infiltration underneath the door into the dwelling unit. A threshold height of 3/4 inch is only sufficient to resist water infiltration in areas of low wind and exceptionally low rainfall. Throughout most of the rest of the U.S., the potential for water to leak into interior spaces under conditions of high wind combined with heavy rain does exist with a door threshold of only 3/4 inch in height.
AAMA points out that these sills can be accommodated within the 4-inch step down permitted between Type Bdwelling units and exterior decks, patios and balconies. Permitting this higher threshold facilitates compliance with Chapter 11. If a higher threshold is not permitted between exterior decks, balconies and patios that serve Type B units and the actual units themselves, exterior decks, balconies and patios could not be installed in R-2 occupancies throughout most of the country without creating a potential risk of serious water damage to the interior of the building. This is especially true along the Gulf Coast and eastern seaboard, where much higher thresholds are needed to sufficiently resist water infiltration under extreme weather conditions.
The AAMA proposal is slated to be presented by Julie Ruth, AAMA’s Code Consultant, at the April/May ICC Code Development Hearings in Dallas, TX.