When remodeling a large home I have to face hot water supply issues. The run from the water heater to the kitchen and baths can be long, and it can take some time for the tap to run until the water becomes hot. There are a number of solutions to this problem, but one interesting option is to use a recirculating hot water system. In this method the hot water is constantly circulated in a loop so you get instant hot water when you turn on your tap.
This type of system uses an electric pump to circulate the water, which can be programed to circulate during certain times of the day to save energy. You may think that this type of system is more energy wasteful than a traditional system, but that may not be the case in a larger home. Think of all of the water that you waste when you turn on the hot water tap and wait for it to heat up. See photo below.