Sunday, October 20, 2013

ADA: Kitchen Design for the Deaf

The architect Robert Nichols ( was kind enough to share this awesome example of accessible design for someone who is deaf. Enjoy.

The kitchen renovation and home remodeling project were completed in Bethesda, Maryland in March 2003. The plans and photographs of the project are placed to demonstrate how the accessible light system and other aspects of the construction simultaneously enhances comfort and safety using the following elements:

Photo 2: Rendering of the kitchen plan. This image, one of these remodeling spaces for foyer area, main stair, workroom and living areas in the house, shows where the accessible light devices are placed in the kitchen. The accessible light system provides a strong flashing alert for the benefit of the hearing impaired resident. 

The residence, which was built in 1986, is located in a suburban area of Washington, D.C. The total area of the three and an half level house is 4,500 SQ FT in a 9,000 SQ FT lot with a swimming pool, outdoor deck, and terrace on the side yard. 

The Kitchen Remodeling included a complete kitchen renovation, which encompassed a living, breakfast, dining, foyer and main stair remodeling with installation of an electrical system for new and existing accessible light fixtures. Because both my client and her housemate are deaf, one dangerous condition needed to be remedied. The residents were unable to hear alarms from the home security and smoke detector systems as well as other sounds from the telephone and doorbell. Clearly, a safe, comfortable, convenient, and communicative accessible light system was the design solution for the kitchen remodeling.

The Notification Control Center, which is a part of the electrical control center in the basement, includes telephone and doorbell controllers, home security, and whole house signaling relay for security and smoke detector. They are connected to the Notification Control Center from receptacles and light fixtures on all the levels. It includes the transmitter relay contact for the upstairs patio door which connects to the visual signal whenever the door is opened without anyone ringing a doorbell. 

The center has two separated security systems, the main security and accessibility system and a back-up system that operates during a power failure. The main system includes a monitor send-off from smoke detectors; clear dome strobes with minimum 50 candelas; carbon monoxide detector; and X-10 compatibility for visual warnings during entry for alarm engagement. The back-up system includes monitor alarm conditions; allowing shared use of strobe lights for telephone and doorbell signaling. 


Approximately 30% of the existing lighting fixtures have been replaced to provide a new flashing signal for both doorbell and telephone in all rooms throughout the three and an half story home. The accessible light system has two separate installations for the alarm signals and flashing lights. For example, when a resident is in the kitchen, and a visitor comes to the front door and presses the doorbell, two signal flashes from under the upper cabinets provide the necessary alert. 

The signaling/relay control center controls both new and existing light fixtures to flash when the doorbell and telephone ring. The project therefore encompasses two solutions for creating an accessible light system in the house. The project remedies the need for an accessible light system by creating a new system which includes new fixtures, and, at the same time, integrates into the new project many of the existing fixtures These solutions supplement new alarm signals installed in living, bedroom, recreation and study rooms with the addition of an installing flashing signal in existing fixtures.


The type of alarm lights for the home security system is a Xenon flash tube with a high intensity strobe lamp. The color of flashing light is clear white. The rate of flashing is 1-3 Hz that indicates flashing per second. The intensity is 75 candela-seconds minimum with maximum of 120. The duration of flashing is approximately one
millisecond (0.001 second). The visual signals produced by these alarms are bright enough to alert hearing impaired residents nearby and safe enough to be viewed directly in every space of the three and half story house. Each visual signal installed in the space is capable of illuminating a rectangular area up to 1,000 square feet. 

See below:

Friend rings door bell.

Sees door light flashing.
Answers door.

Some spaces are divided into smaller areas or have irregular shapes such as the living area. The open space to both breakfast and foyer from the semi-level above needed a combination of visual signals and a smoke detector to be installed. Smoke detectors with visual and audible signals are installed on the same surface and close to alarm light devices for the home security system – see Photos 12. The smoke detectors have built-in transmitters and receivers that are installed on a permanent basis to communicate with the main fire alarm system through the TTY (Telecommunication Device for the Deaf) relay service device in the control system. 

 The smoke detector with signal is not connected to the alarm signal devices when they are installed together on the same wall. The smoke detector is typically activated by built-in smoke sensors. The smoke detector device is similar to another one in the office workplace or commercial space, but the light is still white and the plate is red similar to a fire engine or ambulance light. The smoke detector’s color is white which is matched to the color on the wall. Finally, a deaf resident receives a call from the TTY relay service immediately, because they received an alarm from fire, breaking security or accident through the notification control center in the house.

Robert Nichols, Assoc.AIA
Nichols Design Associates, Inc.

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