MiL's house is a minefield of potential problems.
No shoes in the house - that's fairly common for the continent. I used to take my slippers, but they prefer sandals - go figure.
Of course, toilets feature highly in her concerns. No logs in the bog UPSTAIRS (downstairs is fine). Why ? Because she's on a water meter and is convinced that the one upstairs needs more water to flush. The one downstairs, however, is unheated and very high of the ground (she had it built that way "because it's healthier") and have an "inspection platform" that can make you suffer from severe "splashback" if you're not careful. It also requires a lot more "post operational care", shall we say. Shall we proceed upstairs ? Maximum of one light on at a time "to save money". The upstairs bathroom has a shower and a bath. The bath is only ever used to wash hair in, as a bath is "too expensive". The shower is temperamental and takes ages to warm up, but if you are in there longer than 90 seconds, and she's in the area, she will bang on the door to stop you "wasting water". You have to wash like you are on a boat. Wet yourself, turn the shower off, soap yourself, rinse off, and towel dry yourself. Towels must be hung a certain way, in a certain order. Then the shower must be cleaned, the mat on the bottom hung on a certain peg in the shower, and the 3 part door evenly spaced to ensure it dries quickly. Windows are open in the whole house most of the day, even in deep winter "to stop the house getting damp and smelly". She even sleeps with the window open, whatever the weather.
Lighting is often an issue. She had dimmer switches fitted "because if the light is dimmer, it uses less electricity". She only uses one lamp in the lounge with a dimmer switch turned right down for just that reason. She never uses the normal light in the kitchen as it's "too expensive", but is happy to use a strip light in there.
I could go on, but it would depress me further. I have 10 days there this Xmas. Wish me luck.