Hello finally caught up with this thread.
I campaign for safe loos so have been looking at cubicle design for a few years. I can give you my thoughts on why I think there should be single sex changing rooms as a default.
It used to actually discuss in older building regs, that single sex toilet cubicles have gaps (150mm) at the bottom of partitions and doors and gaps could be above a 2000mm door. This was for the following health and safety points:
Supervision
Prevention of Wilful Misuse
Ventilation
Cleaning
‘Supervision’ is making sure the occupant is ok. ‘Prevention of wilful misuse’ is about sex, drugs and vandalism.
I don’t know about changing rooms regulations but I know from manufacturers and cleaners some practical points of gaps and cubicles.
In a swimming pool, obviously humidity is high and you need to decrease standing water and get rid of hairs, plasters, bubbles, urine, blood, chlorinated water that will build up. To wash that all out and drain you need the door gaps. I know from research on toilets, bleach, which is used for preventing mildew and killing germs, is a nightmare for eating through cubicle partitions. Water also warps doors so they don’t shut.
You need ventilation to dry cubicles out as they are constantly in contact with water.
With toilets, doors need to have the ability to be able to open outwards, in case people collapse. There should be simple safety locks, easily released from outside for access in case of emergency. This is particularly important where elderly or disabled persons or children are involved.
So ‘Lockable’ does not mean totally secure. This has been abused and can be a particular hazard in unisex toilets which are designed to be sound resistant and private.
It is much safer, in particular for anyone medically vulnerable, not to be in a cubicle/room that is private. (For example 11% of cardiac arrests happen on the loo). It makes it worse for women and children if it’s a private cubicle/room that is in a mixed sex area. Leisure Centres have defibrillators but if someone starts to feel ill in the pool or sports hall they stop what they are doing and go to get changed or go to the loo. People need to know if they have collapsed in order to use the defibrillator in time.
According to one toilet manufacturer, they suggested a 5mm gap was needed from floor to door to prevent voyeurism. But then you lose the health and safety benefits. Voyeurism is a male crime. In toilets, I think the biggest threat is from hidden cameras. They are pretty ubiquitous now which is why I feel I don’t feel so bad mentioning it as I am not giving ideas to people. Maybe in the tougher humid pool environment they may not last but it is easier to spend time in a private unisex toilet with the extra ventilation and equipment they need, to position and adjust them.
With toilets there is no such new design as a mixed sex toilet with door gaps. In building regs mixed sex toilet cubicles have to be private.
To summarise: I know that if you have cubicles, you need gaps for health and safety therefore single sex cubicles with a single sex area in front of them should be the default.