Public Toilet Cubicle Design in CMU
Written in 2016/11/8, Pittsburgh
Many public toilets in CMU campus are very inconvenient to use for the following reasons: the poorly designed toilet paper dispenser, the problematic automatic flushing and the inconsiderate cubicle door design.
The toilet paper dispenser in CMU is poorly designed because of its height relatively to the floor, its location relatively to the person who is sitting on the toilet bowl, the size and the problematic hand-sensor, which often leads to unnecessary waste on toilet paper.
This is my first year in Carnegie Mellon and I was confused and shocked when I used a public toilet with an automatic toilet paper dispenser for the first time. First of all, the height of the automatic toilet paper does not fit with the common human reach. The automatic toilet paper is located a little behind the person and the height of the toilet paper is pretty low. So every time I had to bent down and turn around to reach the toilet paper in a very uncomfortable and awkward way. Second, the toilet dispenser is too large, taking up a lot of space and makes the cubicle seems much more crowded than it actually is. Third, the toilet paper is sensor-operated, which means when a person put his or her hand under it, it will sense that there is an object and pull out toilet paper automatically (see illustration 1). This is the part that drove me mad: I had to wait quite a while for the sensor to sense my hand and spit out toilet paper. Sometimes the paper didn’t come out at all, while sometimes it kept pulling out paper even when I had already removed my hand. Since the height of the dispenser is pretty low, the result was leaving lots of toilet paper on the floor (see illustration 2), yet there is no sanitary bin in the cubicle, so you can imagine how would the next user feel entering the space. And if I want to get another piece of paper, I have to discard the part on the floor with a guilt feeling of wasting precious resource on earth.
I couldn’t understand why the designer of public toilets in CMU put such a big and cumbersome automatic toilet paper dispenser, which often surprisingly pulls out toilet paper at the wrong time, in such a small cubicle. At first, I thought this is culture difference because I’m from China and the design of public toilets in China is quite different from the ones in here. But then I found out during the conversations I had with my classmates that American students also find it very confusing. When I brought up the automatic toilet paper during conversions, people became so excited and they kept talking about how bad they think the design is and their funny experience with it. One of my friends told me that one day she put her feet under the dispenser unconsciously, it started to pull out toilet paper and she was aback by the sound. We laughed. To summarize, this automatic machine simply can’t fulfill its duty as a toilet paper dispenser, which is allowing people to get the toilet paper when they need it in a comfortable way.
Another poorly designed element in the cubicle is automatic flushing (see illustration 3), which is actually quite common nowadays. But the problem is that it often flushes at the wrong time. This can be very awkward because it might flush the toilet when you are still sitting on it and splash the water all over the place, or flush before you throw the rest of the toilet paper so you will have to flush the toilet again, and the only way to do this is to put your hand in front of the sensor and pretend it is the next user, which can be so inconvenient that most of the people simply give up and leave the toilet bowl a mess with used toilet paper in it for the next user.
The last reason why I think many public toilets in CMU are inconvenient is the door design of the cubicle (see illustration 4). I had to pull instead of push to open the door from the inside. It is not very friendly especially to people who have a large backpack on their back. Since pulling the door takes up almost one third volume of the cubicle, people have to squeeze themselves to get out in order to minimize body contact for hygiene reasons. Also, from the hygiene perspective, the door lock design is not satisfying because it requires too much hand contact to operate (see illustration 4), which can potentially lead to bacterial transfection between people.
Despite these obvious pain points, I’ve noticed designing public toilet is far more complicated than I thought after doing the research on this topic. In a publication by the Restroom Association (Singapore), A Guide to Better Public Toilet Design and Maintenance¹, it is said that a well-designed public toilet has to be:
(a) Clean and dry
(b) Well ventilated
(c) Easy to maintain
(d) Carefully planned layout
(e) Friendly to persons with disabilities and special needs.
From this we can see that lots of factors need to be taken into account for a public toilet design. To further introduce the design principles in detail, the author points out that “placing the appliances in order of use simplifies the circulation and reduces the distance travelled by the user. Using sensor-operated appliances should encourage hygiene”, “public toilets should be designed to minimize hand contact as far as possible for hygienic reasons”. Also, the Code of Practice on Environmental Health² clearly indicates that “cubicle partitions shall be of rigid design and wall or ceiling hung, where practical, without leg support for easy cleaning of the floor”, “the toilet cubicle should be designed to minimize waste on resources like water and toilet paper”. Based on these principles and the pain points I pointed out above, I had a thought of a new public toilet design.
The automatic toilet paper is not necessary. It not only takes up a lot of space but causes waste on toilet paper. There is a design theory in Japan called Product Fitness 80, which asks the question “what would happen if we used 20% less materials and energy to make products?”. It is a design theory developed by Naoto Fukasawa³, who believes that a good design should be built by both designer and the interaction between the user and the product. In other words, that 20% is for user to interact with the product. In my opinion, the automatic toilet paper took away a large part of the interaction and added elements that are unnecessary. A small simple toilet paper would meet the user needs perfectly and can be very elegant as well (see illustration 5). The extra waste of toilet paper can also be alleviated since there will be no toilet paper littering on the floor due to false automatic operation. The toilet paper should be placed on the side of the cubicle and should be placed a little ahead of the person. To make the experience of pulling out toilet paper smoother, there should be a 90-degree angle between the wall and the toilet paper (see illustration 5).
A small sanitary bin is necessary so that people do not have to throw the used toilet paper or pads into the bowl. For hygiene reasons, the sanitary should have a lid and should be sensor-operated: when people put their hand over the bin, it opens automatically, and closes automatically once people move their hand away. The bin shall preferably be hung on the side of the wall just next to the bowl (see illustration 6), so as to avoid misoperation and facilitate cleaning.
As for automatic flushing, although it guarantees hands-free operation, it can often be triggered at the wrong time and cause inconvenience for people. The timing for people to flush the toilet is hard to measure: sometimes people need extra time to throw in toilet paper before flushing, sometimes not. A foot-operated flushing trigger can solve the timing problem while keeping people’s hands clean. And it is more environmental friendly because people would have to flush twice if the toilet flushed at the wrong time. The foot operator should be placed a little away from the bowl, so as to avoid people being splashed, but not too far, or people would be confused about what this button is for. (see illustration 6)
The last issue is how to allow people comfortably exit or enter the toilet cubicle with minimal body contact. A door that can be pushed open from the inside would address this problem. However, the only concern is that when pushing the door, one might hit someone else who is crossing the toilet hallway. If the toilet public space is big enough, this should not be a concern. But if the space is rather limited, a two-leaf door can be introduced as it can save more than 50% space when pushing open. The door shall preferably be foot-operated, and the operator could be placed just next to the door and should take up a different form from the foot operator for flushing in case of people confusing with these two. (see illustration 6)
As described in illustration 6, the new toilet cubicle design should be more user-friendly than many ones we have in the campus. This design guarantees minimal body contact with objects and discourages unnecessary waste on resources while keeping everything intuitive and simple.
Sources:
1. Anon, (2016). [online] Available at: http://www.toilet.org.sg/articles/GuideBetterPublicToilet.pdf [Accessed 20 Oct. 2016].
2. Anon, (2016). [online] Available at: http://www.nea.gov.sg/docs/default-source/public-health/COPEH/code-of-practice-on-environmental-health.pdf [Accessed 20 Oct. 2016].
3. Naotofukasawa.com. (2016). NAOTO FUKASAWA DESIGN. [online] Available at: http://www.naotofukasawa.com [Accessed 21 Oct. 2016].
