Public toilets are places where one is compelled to ease oneself in unfamiliar surroundings among strangers of the same sex. Therefore, the fundamental principles of the design of toilets include psychological studies and not just physical clearances and space requirement.
It is difficult and costly to insulate the toilets acoustically and this problem can be resolved by planning isolation as much as possible. No unsupervised installation can prevent vandalism. Even with the most vandal-resistant appliances, an unsupervised facility will eventually become sub-standard. In most cases, facility engineers and cleaners play an important role, which will result in well-maintained toilets. However, all designs should allow for individual items to be replaced. Pipe work, traps and electrical supplies should be concealed for aesthetic and hygienic reasons.
Layout
Public toilets should be designed to minimise hand contact as far as possible for hygienic reasons. Electronic products for toilets such as flush valves and faucets require minimum maintenance but offer enhanced operations that promote sanitation and perceived cleanliness because of hands-free operation. There are several screening arrangements for installations showing the visibility from outside in each case. Consideration should be given to the positioning of the mirrors and to the gaps created by the hinges. For example, the access entrance to male public toilets should not open directly to the urinal area. Avoid entrances opening onto a wall surface with the mirror reflecting the urinals.
Directional signs leading to the toilets should meet the needs of the Handicap Welfare Association (HWA). The detailed requirements can be found in Building and Construction Authority’s (BCA) “Code for Barrier-Free Accessibility in Buildings”. Location of toilets should not be too remote from main traffic area to avoid long distance walking for the aged with weak knees. It has to be easily accessible for those with urgency and for better personal safety for the user. Further to this, signages used should be sufficient and prominently displayed in all main traffic passageways, so that the user does not need to ask for directions. Signages used should show contrast of dark solid figure against a white background and significant to be seen by the visually handicapped and the aged. Fancy signage using “Queen” and “King” or “Hat”, “High-heel shoes” are confusing and should not be encouraged. It is not easily distinguished by the visually handicapped and the aged.
The ratio of fittings in male and female toilets should be one WC & one urinal for male: two WCs for female.
As far as possible, fixtures such as urinals and WCs should be fitted back-to-back with common pipe ducts in between.
All public toilets should be mechanically ventilated. Small public toilets should be fitted with an exhaust fan as minimum.
Lighting
A well-designed lighting system will save electrical energy and improve the appearance of the toilet. Poorly designed fixtures with discoloured diffusers go a long way to make a toilet dingy. Dark and shadowy, off-coloured lighting can create the impression that a toilet isn’t clean.
All public toilets should be provided with warm-colour lighting for general lighting as well as down lights above the wash basin/mirror. The minimum general lighting level is 300 lux. Warm-colour lighting aids in creating a better ambience in the toilets, which in turn encourages more care and responsibility from the users.
Materials
Examples of good materials:
- Floor: Non-slip ceramic tiles, natural stone, homogeneous tiles, terrazzo
- Wall: Ceramic tiles, natural stone, homogeneous tiles, stainless steel, enamelled steel panels, glass block, aluminium panels, phenolic cladding.
- Ceiling: Mineral fibre board, fibrous plaster board, Aluminium panels or strips. Non-slip homogeneous tiles are often selected because they are durable and are relatively easy to clean. The walls should be tiled, allowing the cleaners to sponge down the walls and floors thoroughly with little difficulty. Another alternative is to use ceramic tiles or wall cladding.
Wall and floor tiles of large surface areas are encouraged for easy maintenance. The tile size should be at least 100mm by 200mm. Alternatively, any of the panels listed above could also be installed at the walls.
The most common type of ceiling finishes includes calcium silicate board and suspended ceiling tiles. If there is piping above the ceiling, for example, suspended tiles will permit easy access for maintenance and are more easily repaired in the event of spot damage. Calcium silicate board may be better suited for applications where access above the ceiling is not required. When the time comes for renewal of ceiling finishes, it is far less expensive to repaint calcium silicate board than to replace ceiling tile.
Use colours to brighten the toilet, create interest and produce a conducive environment. Colour, achieved with materials and lighting, is one of the vital ingredients in creating ambience. It can be part of the tile or stone finishes, or added to the applied finishes such as the enameling on steel or aluminium. If paint is to be used, it should be restricted to areas that are out of reach, e.g. ceilings.
Urinals
All urinals should be fitted with a flush valve and an automatic flushing device. The fixture should be concealed for easy maintenance and to deter vandalism. Urinals should be individual wall hung units, more than 300mm wide, and the lip of the collection area should project from the wall by at least 300mm. Space around urinal(s) should be in accordance with Appendix I. Urinals should be separated by modesty boards of not less than 300 x 800mm (height). If two or more urinals are installed, one should be installed at child’s height. As a further enhancement to keep the urinal areas dry, stainless steel grating could be installed over the drainage and below the urinal bowls.
Water Closets
An ablution tap coupled with hose and a spring-loaded nozzle should be installed in at least one WC compartment in male and female toilets. Floor trap should be provided within the WC where it is fitted with the ablution tap. The flooring of WC cubicles should be properly graded towards the floor trap so as to keep the floor as dry as possible. That particular cubicle should have signage displayed for easy identification.
Washbasins
Washbasins should be substantial in size. The basins should have a minimum size of 500mm in length and 400mm in width. The space around wash hand basins should be in accordance with Appendix II. All wash basins should be installed into vanity tops, and located beneath the vanity. Vanity tops should have backsplash and apron edges.
The water pressure and tap/wash basin position should not cause water to splash onto user’s body during activation. In order to keep the floor dry, the vanity top-cum-wash basin should be installed outside the toilets for common use by all. Liquid soap dispensers, paper towel dispenser or hand dryer and litter bins should be installed adjacent to the wash basins.
Provision of facilities
All public toilets should be fitted with:
- Waste bins inside each male and female toilet and outside toilets located directly below or in close proximity to the washbasin vanity.
- Either paper towel dispenser or hand drier, directly above or in close proximity to the washbasin vanity.
- Sanitary disposal bins in female toilets
- Suitable air fresheners to promote a fragrant, pleasing environment. Any airfresheners spray should avoid spraying directly at user’s hair, face and body. It should spray away in non-traffic directions or upwards.
- Sanitizers in each WC bowl/urinal fitting.
- Wash areas should also be provided outside public toilets serving wet markets and beaches.
- A slop sink and it should preferably be housed in a separate compartment.
Special Needs
- Diaper changing station.
- Toilet for the handicapped:
Where sanitary provisions are to be made for wheelchair users, such provisions should be in accordance with the requirements stipulated under BCA’s “Code on Barrier-Free Accessibility in Buildings”. The wash basin in handicap toilets should be within reach from a seated position so that the handicapped can do his washing without shifting himself.
Installation Standards
All pipe works should be concealed, except for final connections to the fixtures. Pipe work exposed to view should be chrome-plated. Avoid surface mounting of cables. They should be fully concealed. Avoid sharp corners or edges. Coved tiles or PVC strips should be provided along these edges as far as possible. Access panels to pipe ducts should be located as far as possible in inconspicuous areas. Mirrors should be flush with the wall surface.
Ventilation System
Proper ventilation of a public toilet is one of the biggest priorities. Ineffective ventilation can make a public toilet unusable, even if it is well designed. Effective ventilation ensures that vitiated air is quickly extracted, and helps avoid dampness and subsequent growth of mould on floors and walls. Toilet air should be extracted to the outside by a mechanical ventilation system at a rate not less than 15 air charges per hour.
The mechanical ventilation system of exhaust fans and, where applicable, ventilation ducts and grilles should ensure that every part of the toilet is within 3m of the fan inlet or an intake grille, measured horizontally. Preferably, intake grilles should also be provided at low levels near the WCs to enable foul-air to be extracted quickly before diffusing into other areas of the toilet. Where service access ducts are provided, these should be connected to the toilet exhaust ducts to extract air at a rate of five air changes per hour.
The make-up air to the service access ducts may be taken through extract grilles installed at low level on the walls between the WC compartments and the access duct. The exhaust air should be discharged to the exterior of the building at a position at least 2m above the pavement level and at least 5m from any window or fresh air intake.
Replacement air should be supplied to the toilet to make up for the exhaust air. The replacement air may be taken directly from the exterior, or from adjacent spaces that are permanently air-conditioned or naturally ventilated.
The replacement air may be drawn through louvres in the doors, cuttings under the door, or other openings. If replacement air is taken from the exterior, the quantity shall be lower than that of the exhaust air so that a lower pressure is created in the toilet, which minimises the possibility of vitiated air entering the adjacent spaces. Replacement air should preferably be discharged close to the floor level near the wash basins to help keep the floor dry.
Air locks should be incorporated to separate toilet areas from food consumption or preparation areas.
Looscaping
The ambience of public toilets can be enhanced further by:
- Introducing easy maintenance plants inside the toilets as well as surrounding the public toilets.
- Placing wall pictures with delicate lighting on them.
- Placing ornaments or sculptures at the ‘dead’ corners of the toilets.
Unique Eco Toilets
In a recent innovation, students of S J college of Engineering, Mysore, have come up with a new eco toilet model. This new dry toilet has no flush system. Water is used only when the user washes. There are two concretised pits created above the ground level, each with two compartments – one for faeces and the other to collect urine. There is a separate arrangement to collect used water, which is allowed to soak in the soil. The toilet can be used by a family of five for a period of six to eight months.
The separate concertised pits ensure the faecal waste & water/urine do not mix as it cause a stink. After every use, a bowl of soil and sawdust or husk or green leaves has to be put into the toilet. Once the faecal pit is full, the pit has to be closed and the alternate pit has to be used. The first pit will remain closed for two-three months by which time it will degrade and become humanure (biofertiliser).”
The pit containing urine can be directly used on plants as they have a high level of nitrogen content. The eco toilet can reduce water usage in toilets by 80-90%. Over 400 such toilets have already been set up in Mysore, with 1,000 more to be set up in Hunsur region.