Typically, we do not do the side walls on backsplashes. It looks cleaner and features the tile if you don't do a side splash particularly in a Powder Room. It is a personal preference and usually only done when the counter is very small and there will be a lot of splashing i.e. kids bathroom. You can also turn the liner (blue liner on top) down on each end of the backsplash to finish off the sides. Hope this helps! Best, Stephanie with Bella Villa Design Studio, Austin, TX