Before spec'ing a shower in a truck decide how often it will be used and if the cost of the shower out ways the usefulness of storage and the ability to haul more freight.
If you are thinking about putting a shower in your truck sleeper, talk to people who have them. Would they spec one again if they had it to do over again? Why or why not?
In Diane's and my case, the answer is yes. Yes we would spec a shower again. Even though we use it very little and even though it added expense to the sleeper, we would spec it again. That shower provides more benefits than the ability to use it when a truck stop shower is not otherwise available, and they provide the reasons for putting a shower in our truck, and why we would do it again.
However, if we were to build another truck, there would be no need to spec the sleeper again. We'd simply take the ARI sleeper that has held up and served us so well with us to the new truck. That's one of the big advantage -- if not the biggest -- of having a booted sleeper instead of an integrated one. You can take it with you to your next two or even three trucks if you wish. There are drivers out there who have done exactly that.
You might own three trucks in an expediting career, but if you do your sleeper right, you will only have to buy one. There is a big cost savings in that. So if saving money is your goal, think about a booted sleeper before you think about a shower. And when you find yourself spec'ing a sleeper that will be yours for as long as you are in expeditng, that shower may not be such a bad idea after all.
Regarding storage space and the ability to haul more freight (box size), if you are going to trade a shower for storage space, the sleeper size would not change and your box size would be the same. If box size needs to grow, the sleeper must shrink, and it does not matter if it is a shower or storage space that is given up. A smaller sleeper is a smaller sleeper.
Finally, since the shower is used very little, that space is used as storage space. You store stuff in it until you decide to use that space as a shower. Then you set the stuff out, take your shower, clean and dry the space, and put the stuff back. Need more storage? No problem. Use the shower. Need a shower? No problem. Use the shower.
Just one more thought if I may. We're not talking about a shower only. It is a shower/toilet combination. The toilet is frequently used. Need to save fuel and time by minimizing your stops while your co-driver is driving down the road? No problem. Use the bathroom in the truck.
Oops ... one more thought. If you have a dog or dogs in the truck, the shower would be a fantastic place to dry them off when they come in wet and wash them when they need a bath (big hounds excluded).