Just in case people are confused about refurbishing toilets, for England:
In the Secretary of State’s view, requirement [for building regulations of toilet facilities] is met by ensuring all of the following.
a. Separate single-sex toilet facilities are provided. Universal toilets can be provided in addition to single-sex provision and where space allows. All toilet accommodation should have clear and appropriate signage.
b. Where space precludes single-sex toilet facilities from being provided, fully enclosed universal toilets should be provided.
So for example in b is where you only have one toilet in premises like a small cafe.
The definition in Document T is:
Toilet facilities: Sanitary accommodation that contains water-closets (WCs) and/or urinals, along with washbasins and hand-drying facilities.
This strikes a sensible balance where space only allows one toilet. Misuse in such a toilet is less likely due to the turnover of occupants and greater supervision if something goes wrong. They do need more cleaning and good ventilation though.
Hopefully similar clarity on changing rooms will be made as accessible to read soon.