Pausing for a moment, can remind ourselves of the base regulations:
From the Workplace health, safety and welfare. Workplace (Health, Safety and Welfare) Regulations 1992.
Sanitary conveniences
20.—(1) Suitable and sufficient sanitary conveniences shall be provided at readily accessible places.
(2) Without prejudice to the generality of paragraph (1), sanitary conveniences shall not be suitable unless—
(a)the rooms containing them are adequately ventilated and lit;
(b)they and the rooms containing them are kept in a clean and orderly condition; and
(c)separate rooms containing conveniences are provided for men and women except where and so far as each convenience is in a separate room the door of which is capable of being secured from inside.
(3) It shall be sufficient compliance with the requirement in paragraph (1) to provide sufficient sanitary conveniences in a workplace which is not a new workplace, a modification, an extension or a conversion and which, immediately before this regulation came into force in respect of it, was subject to the provisions of the Factories Act 1961, if sanitary conveniences are provided in accordance with the provisions of Part II of Schedule
In what way is the EHRC interim guidance disagreeing with this statutory guidance?
Separately, @Tandora, I am highly entertained by your idea that the net result of the SC ruling will result in a diminution of single sex facilities in favour of universal facilities. Universal facilities are very inefficient In terms of space and as both lessors and lessees want to minimise costs, landlords will provide the legal minimum sex based toilet facilities.
But you are free to create a different legal and financial framework.