You can have unisex but there has to be a provision for separate toilets somewhere in the workplace. I worked at a school once that was threatened by H&S executive because there was a unisex bog on one floor that the female staff all complained about. They said as long as there's female/male only toilets elsewhere on the site, the school was legally allowed to do it.Unisex is fine, just not women having to run the urinal gauntlet.