If you install the plumbing too late, it can delay the finalization of your project. Getting a plumber to come in at the last minute and complete the project can be difficult. By planning ahead and installing plumbing at the right time, you can avoid any delays in the completion of your project. Additionally, you may run into an issue where you have additional work to do after the plumbing is installed, such as moving fixtures, adding tile, or painting the walls.