No a shower curtain is not needed. The concept is that the door covers up enough of the space to block any water from getting out of the shower. There are different sizes and also full width doors that are available. It really depends on what you are looking for.

I want to replace the bathtub as well - saw one of these in a hotel in Rome, Italy -great design!

they do look great

This is a European design tub door that does not need a shower curtain. DreamLine offers many style doors for your bathtub. It really depends on what you are looking for. Thank you for your interest in DreamLine and for shopping Houzz.