Japan Toilet Association Normalization Research Committee held an interactive lecture entitled “Toilet Needs Survey with Human Attributes; Five Senses and Mobility” by Yoshiyuki Ueno, Ph.D., vice chairperson of Japan Toilet Association (JTA) on 28 September, 2024, Saturday. This is a summary of the lecture notes. (reported by Ms. Erina Yaguchi)
1．Introduction
Normalization Research Committee (hereinafter described as “N-Lab committee”) is in JTA. It focuses on the toilet issues and the major role of this committee is to consider the necessity of the toilets, which are essential for the social activities, and what toilets should be like that everyone can use safely for not only people with disabilities and the elderly but also many other people to live independently. The group has been holding the seminars since 1997, but suspended from 2020 by COVID-19 pandemic.
We resumed our activities last year after the Japanese government declared the termination of COVID-19 emergency state. N-Lab committee member, Mr. Yasuyuki Hoshikawa held a “Good Things Survey” seminar last year, and this year another seminar was held by N-Lab committee member.
2．Contents of this N-Lab committee seminar
2-1. Title: “Toilet Needs Survey with Human Attributes; Five Senses and Mobility”
2-2. Format: A highbred interactive style of the lecture room and remote
2-3. Date and time: Saturday, 28, September 2024, 15:00-17:00 JST
2-4. Lecturer: Yoshiyuki Ueno, Ph.D., Vice Chairperson of Japan Toilet Association
He is a former professor at Faculty of Engineering, Department of Design Science in Chiba Institute of Technology. His study areas cover the architectural planning, interior design, and ergonomics. He has been engaged in the research about improving the comfort and ease of use of the various products for the everyday life. For instance, the functionality of chairs and seats, the ease of use of the writing utensils, and barrier-free design.
1) His research fields
Architectural planning, ergonomics, interior design, product design, barrier-free design
2) His major achievements
– Research on the functionality and evaluation of the chairs and seats: This is also the subject of his doctoral thesis. He surveyed on the importance of the chairs and seats in everyday life. He conducted the interdisciplinary research on the comfort, ease of use, and the effect on the body.
– A manual creation about the barrier-free education: He created an educational manual to let make understand of the barrier-free design and put it into practice.
2-5. Content:
It shall be necessary to clarify how to overview the subject users when considering the normalization of the toilets. So far, the attributes of the toilet users tend to be limited to the disable people in the previous surveys.
Considering this background, N-Lab committee has been conducting research on;
① Identify the subjects of the toilet users
② Survey the toilet needs under the environment, equipment, and space according to the user attributes
③ Reflect these results to the toilets of the common, public, private ones. This time, he introduced the overall vision by these researches.
1) The user attributes
The toilets can be grouped into two; the home and public toilets. The difference is that wearing shoes or not. There are a few centimetres diff when sitting on a bowl in the toilet. The varieties of the public toilets are men’s toilets, women’s toilets, children’s toilets, and multi-purpose toilets. Then it is necessary to identify which users will use these toilets. Therefore, the designers are required to recognize the user’s physical position, physical ability of the range of the motion and strength, etc.
So far, the toilets have only been divided into “Common Toilet” and “Multi-function toilets.” From now on, it is supposed that the group will be modified to “Common Toilets plus Functionally Separated Toilets.” It may seem that the number of the toilet cubicle types must be increased with more options. However, some consideration must be given to ensure that users can choose the variety of the toilets without hesitation before entering it. A careful guide of this information must be required.
2) The toilet user attributes
The crucial factor is that the person can or cannot use it. This is not enough to know the name of the disability, the assistive device, or the disease. Therefore, we must recognize the user abilities. It is necessary to know the physical condition, functions, and abilities of the five senses, disability level, or Activities of Daily Living (ADL). In other words, how to organize and classify “people’s attributes of the toilet users.”
It is necessary to refer to the body position, ability to exert force, movement characteristics with the five senses, the perspective of universal design, user engineering (Ref. “User Engineering” by former Prof. Masaaki Kurosu), Quality of Use (Ref: “Usability” by Prof. Naoki Hirasawa), user-centred design, inclusive products (Ref. Public Interest Incorporated Association, The accessible Design Foundation of Japan), the disability level rating table for the users with the physical disabilities, Paralympic classification, and ADL, when considering the human attributes from the perspectives of the architecture, interior design, and ergonomics.
3) Human body size to create and use the equipment
The static and dynamic human body size is required when starting to compile data. The motion space by the user is a critical element of the design. It is necessary to consider the size of the space by taking into account not only the static size, but also the margin of the user moves.
There are JIS (Japanese Industrial Standards) on the toilet bowls. However, the toilet seats vary in thickness depending on the product. This can affect significantly for users when sitting on it, and then the total height with the toilet bowl and seat must be considered in conjunction.
4) The easier obtaining information with the five senses
The human sensory receptors (five senses) include sight, hearing, touch, taste, smell, as well as intuition and predictions. About 80% of the information is dependent on sight among the five senses. Therefore, it is necessary to take into consideration for those people who cannot use the five senses or who are hypersensitive. How do we compensate for that visual information? It is also crucial point how to deal with it. The five senses role an important factor in many situations, such as daily life or avoiding danger. Therefore, the sufficient consideration is required in the spatial and product design.
We must consequently pursue to develop “Objects and Spaces” that the users will be included. We must consider the tendencies and habits common to many people (Population Stereotypes) for the toilet design.
5) A list to envision the potential toilet users
A list was created to reflect the backgrounds of many users and clarify their positions. This list was organizing items from the ergonomics, medicine, rehabilitation, sports science, etc., in order to identify the genuine toilet users. This list of the toilet users can be referred by the people on the design and supply sides. This can be referred by the toilet users, designers, installers, and managers. Its style must be such as “a Guideline” that can be used as a reference for the balance of the toilet spaces and the potential users.
6) Is it enough to think the toilet is just a place to defecate by the users?
The goal of a functionally separated toilet must be ease of use. Anyone will easily find the toilet without getting lost. Those can be recognized whether there are any facilities in the toilet. Those can be identified the layout of the facilities there, and can be operated and used them safely, comfortably, and without any hesitation. There also must be the mechanisms to make it easy to resume the toilet as to its pre-use state after use. It is also crucial to be able to report when emergency situation.
