When adding services or things of that nature, keep in mind retention. Will this make more people come to your gym? Will this keep your members happy? Do a small survey, ask your members if this will ‘improve’ your facility. If your members are happy, you are happy. Also keep in mind that if your going to put in a shower, it will cost monthly to keep it up and your also going to want to have a nice one that will make your members feel comfortable.
Hope this helps,