Passive Solar Overview

A passive solar building is designed and built based on utilizing the constants within the surrounding environment, centered around the movement of the sun.

Passive solar buildings will be warm in the cold winters and cool in the summer if planned and built according to a few passive solar building rules.  Passive solar design works with the sun’s heat energy to both to warm the building and is designed and situated to block the sun in the warmer summer months to keep the building cool.

Passive solar quonset hutThe sun rises in the east and sets in the west.  If a structure has windows on the southern facing side of the building, it can potentially receive the sun’s warmth (heat energy) all day.

In order for passive solar design to function, most of the building’s windows must be located on the southern facing side of the building.

In the summer, the sun travels higher path in the sky than it does in the winter. Thus, if the proper roof or window overhang is constructed, the house can receive the full winter sun, while the house is shaded by the overhang during the summer.

See pictures of the sun’s rotation on the winter and summer solstices.

When a passive solar building is designed and build well, the building simply, passively sits there and will be warm in the winter when it is cold outside, and will be cool in the summer when it is hot outside.
Passive solar design generally works with the following principles:

Diagram of Passive Solar Design at Work

Diagram Courtesy of the Department of Energy

1.  The sun travels different routes in different seasons.  The winter sun travels a lower route in the sky than the summer sun.

2.  If glass windows are located facing the south, in the winter, they allow the sun’s energy to be absorbed and stored within the building.

3.  If the thermal mass is located (usually in the floor and walls) where it can absorb the sun’s energy, it will absorb, then slowly release or distribute the stored heat energy through the evening and night.

4.  If the proper control, or overhang is constructed over the windows, the summer sun can be blocked from entering the building.  The lack of direct sun allows the structure to stay a cooler temperature.

5.  If the building is properly insulated, it will retain its warmth in the winter, as well as its coolness in the summer.

Passive solar design utilizes energy from the sun, using its predictable movements through the seasons to heat and cool a building without any additional mechanical devices (hence the name – passive solar). It can be thought of as the aikido of architecture.



5 Responses

  1. Judy Goldman says:

    I learned something new today.

  2. liam coty says:

    thanx for the help

  3. Megan belt says:

    The first thing that I noticed is that the picture had the sun chapter in the house.

  4. Winton says:

    I have to build this for a school project. im 12. i need some help?


    • Keya Lea says:


      It would be a good idea to get some help if you want to build a passive solar project. You could build one on a smaller scale, perhaps with wooden popsicle sticks for the frame, something that can store solar heat in its mass (like small tiles for the floor), and perhaps use smaller plexiglass for the windows. Remember to face the windows toward the south if you are located in the northern hemisphere, and build a small overhang to keep the summer sun from entering the house. You could use a thermometer in the house to see how well the model performs throughout the day and night.

      Best of luck!

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