Also wood siding on the outside is wearing out, needs to be replaced, looks like they patched it in places with plastic sidding.  

Unless you wish to pay for a lot of plastic surgery or pretend to be someone you aren't get over it.

They exist in both plastic and metal, but I think I'd use plastic in a bathroom. 

White plastic, black letters.

It doesn't cost me much if any more, just some plastic, masks and paperwork.  

you could actually put plastic up before the studs and then staple and. duct tape , then use  regular insulation . i guess depends on what its being used for and where you live as well . i have seen kits on eBay and amazon , may  not be worth it ????

We did not charge him for it, because our contractor cleared it with one of those long plastic snake things and removed a clump of hair.

Be suspicious of replaced plastic  plumbing at the hot water heater and under sinks.

Disclaimer: This is based on adding a door in a single-family home in Missouri; the requirements for multi-family and in other jurisdictions are probably different.If you have any electrical outlet boxes in the fire-rated wall, they probably need to be steel, or the fancier plastic ones... the cheap blue ones aren't rated for it.If you have to bring a pipe through the fire wall, there may be some requirements about that.  

Ask me how I know this....2) the hardware at ikea for cabinets (drawer pulls, etc) is not the best, and needs some patience and tweaking, but can give you a really, really cool look for a lot less than custom.  3) if and when someone tears through the outer laminate (plastic) layer on them, water will destroy them in no time (think under-sink leak)