Already you have left space for 18mm thk single glass.. to insert inside the hollow gap.. A;so a electrical wires in been kept on top, i dont know how u where u wanna used that for, there is no sandwich type glass space over there... Wood u hav already used for panelling & u r looking for glass.. wat type to take... My suggestion will be, u go for clear toughened glass, so that on one side u can fix film, ,,, so that any time if u feel like to change the design u can. but if u for for designer glass or decorative glass, which will not alter later, that will be one time large investment for u ,,, But changing the film will not disturb the entire partition and glass , only reasonable price u can change the entire film as per latest trendz

Do you have a photo of the terrace garden now? There are so many creative vertical gardens right now - I'd love to help come up with the perfect design for your space. I'm sure you've browsed Houzz, but here is a specific search for vertical gardens - the possibilities are endless! https://www.houzz.com/photos/vertical-garden-design-ideas-phbr1-bp~t_724~a_34-281

If the shower area is sufficiently big, I would prefer to opt for glass partition as that ensures that outside dry area does not get wet, which may happen in case of shower curtain. Having said that, I would opt for shower curtain if the shower area is small to avoid accidentally banging my elbow against the glass partition while taking shower and getting hurt.

i cant tear down the wall. how to camouflage the wall? i was thinking of creating book shelves with low sitting arrangement.