I am planning to develop the first floor of my chalet bungalow to include a bathroom. I intend to relocate the cw storage cistern into the loft, it is currently in the first floor eaves. The question is that the hw cylinder is currently on the ground floor, will this need to be relocated to a higher position eg first floor? My understanding is that it is just the cold water storage cistern that needs to be higher up to give the water pressure for the bathrooms.