A viewer from Nanaimo, BC has a bedroom ensuite far away from the hot water tank and wants to know how to cut down the long delay between turning on the hot water and getting hot water at the tap.
Even if you could open the walls and add insulation to the pipe, it would not help the problem. Insulation will help to keep a pipe hot, but not to get hot. So if you have turned off the water for an hour, insulation or no insulation, the whole pipe has gone back to room temperature and you will have to wait again.
Pipe insulation on hot water pipes is only useful on cyclical loads, like a dishwasher, that will use the hot water again in just a few minutes. (A year after this show I found an even better Mitland solution, but read on for good information anyway.)
The only practical way to get hot water to the tap faster is to get the hot water tank closer, or use an instantaneous tankless hot water unit. In both cases, if you use an electrical system, it is easy to do because you don't need a chimney.
You can put a hot water tank or tankless system right in a closet inside or near the bathroom. If you want to do this with gas, they do now make "through-the-wall" units that have no chimney. Like high efficiency furnaces, they recuperate much of the heat in an efficient unit, and in addition use a double lined exhaust duct where the cold air comes in around the outside of the hot gasses going out. This allows you to install them anywhere on an exterior wall and have the exhaust go right through the wall. Since they use outdoor air for combustion, they can be closed off in a closet as well.
So it is expensive, but not impossible to give that ensuite bathroom it's own hot water supply. Even the Mitland pump is not cheap, but is takes one hour to install and be up and running.