The building has a low-ceiling unfloored basement accessible only from the outside on the downhill side of the house through a wooden hatch. It has a single lightswitch in the center of the room operated by a pullstring.
The building's fusebox (not a breakerbox, one with actual fuses) is in the basement, on the uphillside wall, along with the hot water heater, and uses different fuse types for different parts of the house, dpending on the number of outlets and other expected devices in that area of the house.
The building has gutters along the roof.
The gutters all drain to the uphill side of the house.
The basement walls, since the basement is unfloored anyway, are not waterproof.
in heavy rains, the fusebox will get wet, and pop some fuses. they will need to be replaced by going outside through the rain, and then into the flooded basement, with a flashlight because the open hatch wont be able to provide enough light to see the pullstring of the lightswitch, see which fuses popped, grab the right ones, and go back into the basement to replace them, the whole time hoping random creatures haven't moved in to the likely-barely-used basement that might want to harass them while they're doing so.
Also, the septic tank, though well buried, has a poor seal and is directly in the path of the runoff after it moves away from the building. so it will fill up very quickly with rainwater.
there is a bathroom on both the upstairs and downstairs, and there are no one-way valves in the interconnected sewage pipes. so when the septic tank gets filled up, sewage from the upstairs bathroom can back up and come out the downstairs sink or bathtub drains. the upstairs bathroom is much fancier than the downstairs one.