How long you have to wait for hot water often depends on how good the hot water service layout is, one which has taken into account distances – obviously, the further hot water has to flow, the longer it will take to get there. In new construction, you can keep plumbing runs short by locating bathrooms and the kitchen near each other. In existing ones, you can install an additional small hot water system to combat the problem or a recirculation pump and valve system which will reroute that cold water sitting in the pipes back to the storage tank for heating, and provide instant hot water to every hot water outlet in the house.  A timer-operated system is best for saving energy as it’s only circulating hot water when you’re likely to need it most.