The self built house sits northwest to southeast, the living room on the first floor faces northwest

You provide too little information.

1。There is no place in a house that you can't open the windows of, but it's definitely better to open the sun. East, south, southeast, and even westward are better than northeast and northwest, and as a room, you should open the window to the northwest, so please be mentally prepared for winter.

But you should have your own considerations, and you can grasp this yourself. There will be no conflict between the upper and lower living rooms except the bathroom.

2。It's good to have a river in front of your door. Sunny waters will help improve air quality and daylighting nearby; There will always be a road, otherwise how to get out, so there is nothing good or bad.

There are some troubles in the fish pond behind the house, which is reflected in two aspects, one is that the light on the shady side is poor, if there are elderly people and children passing by at home, pay attention to safety, and do not accidentally fall into the pond; The second is that because there is nothing above the water surface of the fish pond, the air circulation will be relatively fast, and most of the time it is cool, and there is no shelter from trees and houses, which will affect the health of the family to a certain extent in the long run. I don't know how far away from the fish pond is in the back of your house, especially if you love very closely.

All things considered, you can build a fence behind the house and carry a few trees to alleviate it.