As with the electrical installation we fought hard again to stay PVC-free. For the fresh cold and hot water we use copper pipes; long lasting and recyclable. The only draw back is that the price of copper went up quite a bit lately.
Another ecological option are tubes made from polypropylene instead of PVC. Not many builders have switched to use these as it requires investing into special tools in order to install them by soldering (fusiotherm-fitting they call it). Once you have (or rent?! check out Product Service Systems (PSS)- we love those!) these tools, working with polypropylene tubes is much faster and better since no glue is needed and it’s definitely leak-proof. For the small amount of tubes we needed in our little flat it didn’t make sense for us to buy the machinery and we couldn’t find anywhere that lent them to us, hence the copper pipes.
However, when it comes to grey water pipes, we discovered PVC-free ones that don’t need special machines to install them. Instead, you slide the tubes into one another (downhill to avoid leaking) and join them with a rubber band which replaces the screwing system that so often ends up leaking. The Madrid based company AquaTerm provided us with these pipes made from polypropylene which makes them 100% recyclable. Aquaterm have all kinds of piping systems for water and heating installations, all made from polypropylene. There products are TÜF certified and approved by Greenpeace.
Here in Barcelona, they are available at Tuysa.