Bathroom installation preparations on wooden tongue and groove floorboard?

This is an image of the bathroom you have been tasked with installing. It is on a wooden tongue and groove floorboard floor, with all services planned to be located under the floor. In the corner of the bathroom next to the WC pan is a cold main which supplies the boiler jig on the wall as well as the cold water to the bathroom. What preparations do you need to consider before dressing the appliances and getting them ready for installation?