It's common in the Bay Area Ca. for PI's to pick-up the lack of an access panel in a wet wall. Access is, typically, required to the fixture(s) and supplies, but also to the waste & overflow. Freestanding tubs, with their backs and works to a wall, must also be provided with a means of access. Is this a common code requirement across the states, esp. with the popularity of "Whirlpool" tubs etc.?
In the UK, with almost total masonry walls, access panels are rare and not Regs. This can create difficulties, esp. with a nightmare plastic effort called a corner bath - i've never seen these flimsy monstrosities in the USA, thank goodness. Installing them is like building the Bay Bridge, servicing them is a struggle, their works are typically located tight in the inside corner. Given the time and construction that can often go into fitting, even the average, UK style bath panel, then plumbers and bathroom installers of the US can thank their lucky stars.
To continue my rant, about the only thing she says i'm good at.
Europe, the UK in particular has been flooded with homeowner, internet purchased bits and bobs to make up a bathroom's fittings and fixtures. Lack of compatibility, no or weird instructions, pics that refer to other items: for example, mixer taps/faucets might be supplied with no indication as to wether they are high or low pressure - you find out after fitting them. This is essentially from China, however, India, Indonesia and others are gearing up with even weirder flimsier and cheaper stuff -USA beware, this will happen here. Homeowners will, naturally, buy the cheap junk, and you will, naturally, have to earn a living fitting it.