Anthropometry of Wheeled Mobility Project: Final Report

4.3.9 Doorway Design

We did not obtain quantitative data on performance in our door use research. Thus there are no accommodation models for this topic. The results of the door trials identify relationships between structural anthropometry and identify needed modifications to current requirements.

The results of the door maneuvering studies confirmed the importance of many common accessibility code requirements. They also demonstrated a need to make some improvements to standards to provide access for the broad population of wheeled mobility users. The implications of the research findings are summarized below:

A wider clear opening than current ADA-ABA standards 815 mm (32 in.) would improve usability. Adopting a clear opening width of 860 mm (34 in.) would accommodate the widest occupied devices in our sample. This would also be small enough to allow a 91 cm (36 in.) door leaf, a size that is already used extensively for accessibility and fire safety. Consideration should be given to aligning U.S. requirements with the metric system. For example, a 90 cm door is slightly smaller than a 91 cm door but is standard elsewhere in the world and would accommodate our entire sample.

The very wide door that was tested 1041 mm (41 in.) clear opening did not increase the difficulty of using doors. The findings demonstrate that wider doors are better for accessibility and there is no need to put an upper limit on the size of doors in regulations at this time, although doors wider than this could pose some problems.

The lack of differences between the findings for the passage task on the pull sides of Doors 1, 800 mm (31.5 in.) latch clearance, and Door 2, 406 mm (16 in.) latch clearance, demonstrate that an 457 mm (18 in.) clearance required in recessed doors is acceptable although we do not have data to demonstrate whether the 305 mm (12 in.) latch clearance on other doors is satisfactory. In historic preservation, some allowances should be made for difficult renovation issues like the recess in Door 3 where the structure of the building would not only make adjusting the recess extremely difficult and costly but also would also impact its historic character.

Closers are not necessarily bad for accessibility. In fact, they reduce the difficulty of the most difficult maneuvering tasks, i.e. closing maneuver and closing tasks. Their impact on passage through the door indicates that they must be set to the lowest operating force possible to insure that they accommodate the broadest population.

Since the closing maneuver is the most difficult aspect of door use for wheelchair users, development of a low cost electromechanical closer that would not increase opening force would benefit wheelchair users significantly. It should have microprocessor control that would activate the closer only when a door is closing. When opened, a presence sensor could activate the closing cycle when an individual passed through the door.

Automating frequently used doors that are kept closed and require closers will increase accessibility substantially, especially on exterior doors where the operating forces are higher to conserve energy and insure positive latching. Requiring at least one automated door at primary entries would be highly desirable. This would increase usability for more than 10% of the wheelchair users in our sample and have multiple benefits for all building users: eliminating difficulty using the latch, enabling the opening maneuver, and eliminating difficulty closing the door. In addition, with proper placement of an activator to open the door, it eliminates the need for a latch side clearance.