We keep the public spaces of our house set at 62-65 degrees - which, despite one’s initial expectations, is surprisingly comfortable. (Although my husband may differ with me here.)

So, on an ordinary winter day, the living areas of our house that face north are a cool but manageable (depending on whom you ask) 62-65 degrees.

My office, on the other, hand faces south, with a bank of windows reaching 12 feet high that lets the sun in all day long. We knew that without the foliage from the giant beech, poplar and hickory trees in front, the winter sun beats in and helps heat my office somewhat.

What we did not know, til we removed the screens (to aid in watching the eclipse!) that the screens kept out so much light. And therefore so much heat. We decided not to replace the screens and see what happened.

This is what I can report. Here I sit, 2:00 p.m., sleeveless, in a room that is 78 degrees, heated passively by the light of the winter sun.  As long as the sun is shining, my office is bright and toasty. Come evening, however, since there is almost nothing in my office that is designed to hold in the heat, the room cools down pretty quickly.

Which is why I was particularly interested to learn more about passive house technology.

Developed in Germany, modern passive building technology allows homes, congregations, offices to run with almost no reliance on fossil fuels for heating or cooling*. The siting, orientation, materials, airflow design and insulation all combine to create a healthy, comfortable and energy-lite building.

(* For all those keeping score, this statement does not take into account the fossil fuels needed to manufacture the materials or dig the holes or lay the foundation, etc. But the passive home folk DO account for that, that is, they conduct a comprehensive life-cycle analysis when planning your building so you can know from soup to nuts what your building’s carbon footprint is.)

This is not new. Generations of builders worked with the sun and the earth to build homes that capitalized on the free resources of nature. With the heady advent of cheap energy and the seductive promises of early technology, the era of the man-made trumped the wisdom of nature.

Now, we are returning to those lessons of old, blending the most efficient ways of the natural world with the imagination of human ingenuity. There are exciting times ahead.

I wish I had known that when I was renovating my home.

(Photo: my office bathed in December sunlight)