I am creating a wet room with the shower area panelled in glass. I would like to make a niche beside the shower controls but I'm scratching my head about how to make the join between the niche and the glass panel water proof. For appearances I'd rather not have anything too bulky over hanging the edge of the hole in the glass panel. I am looking into premade niche boxes but they all assume you will be tiling over them. I have attached a WIP visualisation of the bathroom. Any thoughts appreciated.