Sound like the lot that "did up" my Dad's place. Installing a shower which we had to put a notice on and uninstall sharpish - it was live! He had to have the place rewired, but at least electricians were ready to do it. My electrical problems are small - a socket attached to the water heater circuit, which is supposed to be dedicated and 30 amp. But it's safe, so long as it isn't on at the same time as the heater (just blows a fuse anyway), so awaits the big rewire some time in the future.
The builders had their own odd plans. My place is a maisonette, with an entrance at ground level, and stairs running up from the door to the next floor. The kitchen lies ahead, the living room to the right. The door at the head of the stairs is into the living room, so there is a sharp right, can't get the bed, wardrobe, sofa etc through turn through the fire door at the top of the stairs. The flight to the next floor runs up from the living room, at the opposite end from the kitchen. There is only one light switch in the living room, at the kitchen end. There is no light on the upper flight. It is illuminated by a glass pane into the living room, and a glass fire door onto the upper landing. (Two way switch, top and bottom.) Going upstairs last thing at night presents problems.