Installing an open shower always involves a conversion. You should check in advance whether the requirements for installation are met. The construction height of the floor is important to consider, i.e. the overall construction of what is called the floor screed. In addition to the flooring, this also includes other layers such as thermal insulation and piping for underfloor heating. For walk-in showers, a specific minimum height is required for the trap. If the construction height of the floor is lower than the depth of the water seal, installation may not be possible or may require very complex and expensive conversion work.
In the shower area, the floor must also have a slope so that the water runs off. For optimal drainage, the slope should be about 2%.
As the shower is a damp area, sealing is also necessary. The degree of sealing necessary (room height or only certain areas) depends on local regulations.