My Site 2 Group

We have low water pressure in half the house and what looks like a hidden leak somewhere behind a wall, so this feels bigger than a standard repair. How do you usually tell whether a company really does full system work like pipe rerouting and leak detection instead of just basic fixes? I found a page describing Advanced Plumbing Services in Sacramento, CA with the categories listed separately, and it made me think about how much diagnostic detail should be explained before any work starts. I am also wondering whether it is normal to get a written diagnosis first or if that usually comes after the inspection. For now I am comparing a few licensed options and paying attention to how clearly each one describes the process.