Happy Winter Solstice!

It’s that time of year when the days are short as the sun travels its lowest and shallowest path across our sky.  Passive solar homes are ones that integrate with their environments and take this into account.

Family Room Windows – Lookout Deep the Sun Radiates into the Space

Family Room Windows – Look how the deep the sun radiates into the living room


If a passive solar house has its windows facing the south, on the Winter Solstice, the sun’s warmth reaches deep into your house to warm it when it’s most needed.

The tile floor (having thermal mass) absorbs the heat and slowly releases it to warm the sun in the evening and through the night.  Learn more about this home located in the North East.

Here are some images of passive solar homes in the winter from past articles.


winter sun on solstice

The sun rises late and travels a low arc across the sky in the winter.


krebs sun living

As the sun travels a low arc in the winter, within passive solar homes it allows sunlight to reach and warm the back wall (having thermal mass) of the home.


The last two images are from an off-grid passive solar Earthship-style home.  Earthships use old car tires as a building block.  The curved back wall covered with adobe is a massive tire wall that holds the sun’s heat in the winter, while in the summer (because the sun does not shine on it – as it travels a high, wide arc) it helps to keep the home cool.



cats like passive solar homes

While this home has a large southern facing deck, in the winter, sunlight reaches into the home to warm all the occupants.

This is from a grid-tied passive solar log home that frequently reaches net-zero in the summer.



Passive solar kitchen

The kitchen is located in the northern-most section of the home, yet the 2nd story windows allow the winter sun to heat the back of the home.

This is from a comfortable, off-grid, super efficient passive and active solar home.

Why does this work out this way?  Because the sun’s movements are predictable.  Building homes to this predicable pattern, using certain materials along with the building’s orientation, allow passive solar homes to be cool in the summer and warm in the winter while using less external heating and cooling costs.

Justin Quinnell's pinhole timelapse photography of sun travel

Time lapse photography was used to track the sun’s movement throughout the year.

Here’s more on the movement of the sun. (As a side note – the Earth actually moves around the sun. We say that the sun moves around the Earth because from our day-to-day point of view, it appears that the sun rises in the east and and sets in the west, moving across the sky.)

sun winter - summer clean 450

This diagram shows the interaction between buildings and the sun on the winter and summer solstices.  Passive solar homes integrate a few basic principles for building: they have thermal mass, windows on the south side, have good insulation and some type of overhand or solar control to block the sun in the summer.


Happy Winter Solstice! After today we’re looking forward to longer days. 🙂



Keya Lea

Keya Lea likes to spend time outside, enjoying the sun.

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