How much is left in the gutter with neighbors on one side?

There is a neighbor's drainage ditch on one side, leaving 1 meter.

1. If it is east and west, it is enough to leave 1 meter under normal circumstances to ensure that both neighbors can open windows for lighting.

2. If it is north-south, there will be problems of sight and lighting and ventilation. If you are in the south, you should reserve a certain distance to ensure the lighting of your neighbors in the north. Specific details, friendly consultation between the two sides. According to the national regulations, it is necessary to ensure that the building height is 1. 1 times, and at the same time ensure the lighting for two hours from winter to morning. This is a city rule, but there is no rule in the countryside.