CreakyBlinder This assessment specifically raises the violation of rights that occurs when schools keep vital information (such as a child's trans status) from parents. Scotland actually has laws making information sharing with parents mandatory unless there are real safeguarding concerns in relation to the parents (which is highly unlikely for most of the kids identifying as trans).
So if your headteacher keeps info about a child's trans status from the parents, and the kid gets puberty blockers off the internet for instance and gets sick, the parents could absolutely sue the school, probably even go for criminal charges (not saying they would be successful, but it's a possibility).
I would also give any headteacher in a school proposing to follow the LGBT Youth Guidance a link to this new assessment and then ask them if their liability insurance will cover them in case of any incidents arising from the school going against existing law and regulations. AFAIK insurance is invalidated if something happens that would never have happened had they followed the law.
GalacticChickenShit yes, it is absolutely worth giving the council a ring.
The regulations governing school buildings in both Scotland and England continue to mandate separate, single-sex provision of sanitary facilities. They looked at changing these regs in Scotland last year, but they didn't, so they continue to apply to new buildings.
And unless the school builds unisex facilities (these are self-contained one-person rooms with an anteroom containing a sink and another room containing the toilet or one-person rooms containing both the sink and the toilet, with floor-to-ceiling lockable doors and walls), they will be in breach of these guidelines (and a bunch of UN articles of the Convention on the Rights of the Child as covered in this new impact assessment).
Mixed-sex sanitary facilities in schools are simply not lawful in the UK. What is lawful, and eminently sensible, is to provide female-only and male-only, disabled and unisex facilities in sufficient numbers to cater to all the children in a school.
Unisex facilities in addition to those for disabled children are of course vitally important as these children are often underserved already when it comes to the number of facilities. Because disabled toilets are unisex already, in many places outside of schools they are often commandeered to be used by those who identify as trans. Which is of course entirely unacceptable.