House Orientation and Summer Heat Control

I recently researched the best way to face a house in order to minimize heating and cooling cost.  The topic is of interest as I would ultimately like to have a cabin on the property I purchase.  I expect to start with the property off-grid in order to save costs which makes this topic especially important. 

The best information I found indicated the main axis of the house should run east-west.  This does not need to be exact as being 20% off does not have a significant impact.  This keeps the sun over the ridge line of the house more than pointing at a side which contains windows.

The front of your house, or the side with the majority of the living area, should face south.  The least used rooms (laundry room, closets, etc.) should face the north when possible.  

In the summer months, the sun will be overhead.  The sun then bounces off the living area windows due to the extreme angle of contact.  This keeps as much heat from radiating through the windows. 

In the winter months, the sun drops in the horizon allowing it to contact the windows at a less extreme window.  The windows are not as efficient at insulating light which enters from more of a horizontal direction which allows more heat to enter during the winter months.

Additional research provides the angles at which the sun contacts the Earth in the south.  At the peak of summer (~June 21st), the sun is at an 86 degree angle but in the summer drops to a 38 degree angle.  At March and September, the sun is between these two angles at about 63 degrees.

If you were to plan perfectly, you could include just the perfect amount of roof overhang (porch, shutter, or awning) so that the window is protected as much as possible from summer heat but not so much that it impacts sun entering when lower in the winter.  This is obviously only necessary on the southern side of the house.  The northern side can have a larger window.

I also found some general guidelines which state to keep window surface area to the following:

South Facing
- No more than 10-15% of floor area
- No more than 25% of floor area of each individual room

North, East, & West Facing
- No more than 5% of total floor area
- No more than 15% of individual room's floor area