Windows are the eyes and mouths of houses and working places (a window glass broken may cause eye problems). Window is an air opening therefore it must be opened either outward or inward not upward nor downward.

 For Upward - downward window, it should never be opened only halfway because air absorbs half on from the back window and outside people may not have good impression in looking through it.
Although climate and geography may vary, and there are various special needs, windows opened to the west may hurt house air. The tough sunset light may cause headaches, irritability and inefficient work. It is better to have a glass ball suspended to convert sunlight into a rainbow of colors and to make up the air in the room and to create the dynamic. 
The window top must be higher than the tallest person in the house. Window should be relatively large. Window curtain may block airflow, views and also opportunity. 

Declination degree.

Window is an air opening therefore it must be opened either outward or inward not upward nor downward.

Beam, hall, wall or entrance door may foretell surprising things, strange things or damages. This sudden change of work may lead to disasters. Working under the spiral stairs is often ineffective because the sloping degree will let the work go away.

Correction: there are some ways to balance, based on personal hobbies. In case the beam or sloping ceiling, we should hang a red tassel or beam to balance the sloping status or build a sub-beam.
The entrance door of a sloping wall is very bad. Especially, when it directs to bedrooms or bathroom, the family members would become the victims of some strange diseases or incidents. To prevent the disasters, we should hang a glass ball at one side of the door. For a big sloping room, we hang three glass balls along it.
If the whole wall is sloping, the air source will be pressed with an angle less than 90 degree.
Correction: put a potted plant at the sloping corner to let the air move.
 

TrieuTiensinh_Geomancer