Drywall Alternative: A Plumbing Access Panel
Cutting open a wall to repair a plumbing leak is a pretty big deal. These holes can be a few inches or a few feet large. Once you have repaired the plumbing issue, you have to contend with the drywall repair. That means a good patch, matching the texture, and matching the paint.
If you want to avoid all the drywall headaches, you can always install an access panel. You wouldn't want this in a conspicuous spot, but it works very well in certain applications. For example, when replacing a shower valve in the wall, it is common to cut the wall open. Your options are either remove and replace ceramic shower tiles, or cut the drywall on the backside of the shower. If the backside of the shower is, for example, in a closet, this is an ideal spot for a plumbing access panel.
The panel will likely be hidden by hanging clothes anyway, and if you ever have a problem with the valve again, you can just open the door on the panel and fix it without having to go through the drywall issues again.
The plumbing access panel is a small door mounted on a frame. The frame is fairly wide compared to the door which allows it to cover a variety of holes from around 6-inches to about 15-inches. It can save a lot of time and frustration. You can paint them to match the color of the wall, or they also come in stainless steel.