The apartment will have FlexPEX pipes that would run from the manifold to the fixture. This provides a more resilient pipe that is less likely to freeze and burst. All lines are 1″ which is required for the sprinkler system. By using a manifold, a home run system is in place. This means a pipe runs from the manifold to the fixture. There are no branches that would have possible points of failure. In addition, if a plumbing line needs to be fixed, then just that one pipe will need to be closed off therefore allowing access to the other water lines.