I am a porch guy. I love the covered outside space. It has been done in many ways and varies based on the climate, but a good screened porch overlooking a mountain valley, lake, river, nice lush field, etc. is the ultimate space. You are protected, but have the 'experience' of the elements.
It is the connection. New Urbanists have made this a key to all of their residential work, connecting the house to the street (thanks Ms. Jacobs), and in any location, a covered porch is the purgatory between the fully enclosed and fully exposed, the ultimate location to test yourself on your ability to adapt to the elements. It was also the location that ancient greeks tested ideas.
Stoicism is a philosophy from the ancient greeks of adapting to the world as you see it. In my former life, this would also be known as playing the ball as it lies. It is interesting that they chose the Stoa (or covered porch) as their inspiration for learning, but it makes sense.
It is the in between. When you have come from a long day in the fields, and want a cool drink before moving into the homestead. Or the space in the public square where ideas are shared between those from 'the other'. It is the transition space in the third dimension as well as the mind. It is protected from the elements, but must also negotiate abstractly with them.
Eichler made this space the core of his homes. In SoCal, this is easier than New England, but it was the place that life happened. He built an atrium in the center of the home that allowed a family to experience this transition at all times of the day in the safety of their own domicile.
The wraparound porch was another on the plantations and Midwestern farms that built this nation. It sheltered and transitioned the people from work to home. It was the gathering place for the women to meet the men form the fields. A place to relax and decompress from both sides. (the 'fields' and the 'women' are metaphors for the hard labor done by both, yet foreign to the other). There they met and transitioned into each other.
This transition is the magic of the porch. It is neither inside or outside, but it is both. With the proper bug screen, this is the space that most in the north inhabit when the season is called summer. It is the place where those of us who prefer the comforts of shelter venture into the wild.