Installing hot and cold water on the roof terrace / frost protection?

Hello,

I would like to install 2 outdoor showers on my terrace (lower level) and my rooftop terrace (upper level). These are located on the 16th and 17th floors, so they are very exposed, and in summer it gets very, very hot and in winter it can be as cold as minus 15 to minus 20 degrees outside with strong wind. It is a bit complicated and hard to understand if you have never been there, so I have attached these mini photos. In the left picture, you can already see two PVC flexible pipes for hot and cold water coming out of the pipe at the bottom right. My plan is to lay these along the left edge of the concrete and then follow the exterior wall upwards. That ends at the second picture (upper level). From there, possibly drill through and continue underneath the railing to the third picture. This rustic wall will be completely renovated and the shower is to be installed there. And possibly a hose connection for terrace cleaning. I also want to install a shower downstairs where the PVC pipes are.

I hope this was somehow understandable; if not I will "professionally" draw on the pictures with paint. My questions are many:

1. What pipes exactly should I use here in terms of type?
2. Is it possible to lay the pipes like this (in the wall?) so that they do not freeze and burst in winter? Or do I have to install a valve? Unfortunately, the concrete is very strong, exterior walls. Or build something on the surface and insulate?
3. If I have to work with a valve, can I theoretically still just turn it on and use it in winter and then turn the valve off and let the shower drain? Is that physically possible with the slope? Or does a water column remain that can freeze and burst?
4. Can I use the shower downstairs, since it comes from the warmer house, in winter? Or can I "wrap" or insulate the pipes so that at least the lower shower doesn’t freeze and is usable with hot/cold water?
5. Due to the weather conditions, can I use normal DIY store fittings there or do I need something like a special outdoor shower with coating?

Please excuse the beginner questions, I have never installed anything outside a normal indoor bathroom before. I am grateful for any tips, have a nice weekend everyone.

Kind regards,
Martin

I suppose if this is supposed to take place on the 16th floor, there will be several other residents living below you. Based on your question, you also have no expert knowledge. Who will be held responsible if water damage occurs below you or if Legionella bacteria form throughout the entire pipe network due to incorrect installation? Even if a professional carries out work on your behalf, you need the owner's consent, unless you own everything.

16th and 17th to be exact! Don't worry, I bought the part of the roof terrace from the owners' association. So I can do whatever I want there, except for causing damage, obviously. And of course, everything will be done by a professional; I couldn't do it even if I wanted to. The crew of craftsmen is practically part of the building; they take care of everything here. And to make sure no damage occurs, I prefer to ask in advance how to best proceed and secure it.

By handworker crew I understand all-rounders, but not necessarily specialists. Whether you can install it freeze-free like that cannot be answered without being on site. Certainly, however, your crew can.

Certainly, but even general tips already help me to understand better and I appreciate any good advice from professionals or also clients who have carried out a similar project.

Is this a condominium? Then you only own the plaster, but not the bricks through which you have to lay the pipe. Bricks and pipelines are common property, you need the approval of the owners to do what you intend.