It is critical to maintain access to key parts of the water and electrical systems. I discovered a really simple approach.
In the picture I have used a 12-inch square access hatch. It fits in a hole cut in the drywall with a spring-loaded mechanism. Easily installed and easily removed for access.
Where did I get them? Well I got this one at Home Depot but I have seen them or a similar approach at RONA, Home Hardware and Canadian Tire.
;-)