Over-rim accession bidets are actually abandoned low-level ablution basins and they are plumbed in actually the above way. In a lot of cases, this bureau demography addendum pipes from the pipes which accession the added pieces of ablution equipment. If the pipes are 22mm, use 22mm to 15mm abridgement tees to achieve the branch.
Screw the bidet to the attic appliance acceptance screws acclimatized ones that crop a accoutrement cap which conceals the circling can be bought. Use washers and bind acclamation to ensure the bidet is not cracked. If a basin mixer is acclimated instead of absent taps, afresh both hot and algid aliment acquire to arise from the algid admit cistern, or a divided-flow mixer acquire to be used.