space for and size of water heater
How much space is needed to house an 80 gallon water heater? What size water heater is needed to service two full bathrooms --with one bathroom having a 5.5 ft. Kohler whirlpool tub?
It is not a condition of how many bathrooms that you have, but the total number of people who will be using it and at what frequency. If you are a family with growing children (or plan on it) then an instantaneous water heater is the solution. This will give you plenty of hot water with no need to wait for the tank to heat the water. If only 2 or 3 people, then an 80 gallon tank with a quick recovery system should suffice with no problem.