Building orientation - how come both summer and winter solstice used for a facade?
I am planning to build a shed atop my terrace. I was analyzing the sun path to determine the overhang length, facade height etc, but got stuck with a conflict as below.
The summer sun's location peaks are on Northern side of a location (or a plot or house), while its winter sun, is at lower angle, on Southern side as shown below, referred from here.
My conflict is as follows. I see in multiple websites, for a glass of a fixed direction (ex, South), they show both summer and winter sun angles. How can that be the case?
Case 1: For ex, let us look at below diagram from here
They have shown both Jun Sun and Dec Sun for a South facing Glass! But, if we look at sun path, only Dec sun may be on South side. Here are 2 months' sun orientation from this wonderful tool.
Jun on northern side of building:
Dec on southern side of building:
So strictly speaking, for south side glass, shouldn't we only consider winter months? And similarly, summer for northern side? Similarly this should not be applicable at all to E-W side right, because there, Sun appears also at ultra low angles, so no point unless a vertical shading (thus recommendations to minimize glass on E-W, as I am from tropical region).
Here is another image with same conflict in same website.
Case 2: Here is another image from another website. 758
Here too, for a single direction glass (presumably North or South), they illustrate both Summer and Winter as below.
How can that be the case??
Case 3: And then another from here
What am I missing?
My understanding is that, if we take North for example, through out the day, Sun's altitude changes, but the maximum of that incidence is at Summer solstice as below.
So in Northern side, if I want to avoid Sun's direct incidence altogether, say from 8 AM to 4 PM and I do not mind the time afterwards as anyway its morning or evening, I should only see for Northern Side, at Summer Solstice (around Jun), from 8 AM to 4 PM what is the min and max altitudes. For my location, that happens to be around $30^{\circ}$ to $78^{\circ}$, which after further calculations gives me a guideline that, my overhang length $l$ could be $1.732h$, where $h$ is height of my glazing, for example. There is no need of Dec calculation on Northern Side.
If my understanding is correct, then it is wrong for those websites to illustrate both Summer and Winter solstice angles on a glass of single direction. Or please correct me where I am going wrong here.
This is blocking my design phase of my shed.
Update:
As <PERSON> pointed out, in some locations, sun always tend to be in north or south. For ex, in northern hemisphere, as you go northwards, sun becomes more and more only available in south, through out the year. For ex, the sun path for Hamburg, Germany is shown below. 371