If the Good Law Project are watching this thread, please can you note I want to keep everyone safe.
I am looking at what trans people are saying about toilets and organisations like Translucent and Stonewall too. If you look at Translucent (2025) and Stonewall (2018) in terms of their literature on toilets, the worst case scenario is a man flashed a transwoman in protest about using the ladies and a transwoman was pushed out of the ladies by two women when they refused to leave. These incidences can not have been nice and there are lots more incidences of people telling others they shouldn’t be in the toilets they are using.
But in absolute terms of being safe in a public toilet you can’t beat a toilet where the occupant isn’t in a completely private place. That has to be a single sex design. But door gaps have being reducing in single sex provision too. It is now 5mm in some school designs. Part of that is because the area in front of the toilets has to be single sex and in ‘inclusive’ toilets it is not. If it’s ambiguous, or mixed sex, the obvious thing is to make it all private, which coincidently seems to be your argument. ‘Gender neutral’ designs are always completely private.
If you want to make safer toilets for transgender people, you should argue for a U.K. toilet design first - make mixed sex toilets with door gaps. These are not allowed under building regs (Document T which uses bs6465 as a base) and 1974 and 1992 legislation, so you could use that 500k you’ve raised to help you sort new legislation out. I would bet no biological women would use them. I don’t think most biological men would be that happy either.
You will also have problem with voyeurism laws and Section 71 of the UK's Sexual Offences Act 2003. This section makes it a criminal offence to intentionally engage in sexual activity in a public lavatory. An activity is considered sexual if a reasonable person would consider it sexual, regardless of the person's purpose. Making toilets private has handily avoided too much use of Clause 71. Out of sight, and all that. But it also protects transgender people if they are worried about assault, sexual or otherwise. Most men aren’t bad. Most men will come to another man’s aid if they were being assaulted, or at least raise the alarm if they had an idea what was happening.
I believe transgender people are still safest in the toilet (with door gaps) for their biological sex. If they do not use the correct toilet for their biological sex, then legally all toilets should change to universal design. This disadvantages everyone and there will result in more deaths and assaults that could have been prevented. It will be the most vulnerable that suffer.