To save on your electric bill, you want to protect your house from getting too hot in summer and loosing the interior warmth in winter. Getting overhangs and shading to do this is a crucial factor in passive solar design.

The basic principles of a passive solar design are: 1. Don´t let the sun shine through your windows in summer. 2. Get as much sunshine through your windows in winter.  But is it possible to do both at the same time? Sure. Provide shade to your house!

Rule_1. Getting an overhang

Getting an overhang to protect from the sun is a simple, cheap, excellent and fundamental measure in a passive solar design. In summers, when the sun is higher, the overhang protects the interior of the house from the sun´s heat entering. In winters, when the sun is much lower on the sky, a well placed overhang lets the sun enter the house completely and heating up the interior walls and floors.

Rule_2: Size it correctly

An overhang should be sized correctly in a passive solar design. To protect from the summer sun, they should be standing out from the house sufficiently. However, not too much as you would like the winter sun to enter as well.

Rule_3: More suggestions: canopies, blackouts, curtains, trees….. 

Overhangs according passive solar design techniques keep the sun from entering a house too much in summer. But there are more suggestions to keep the sun out: get canopies to provide shade to your windows, cover skylights or other windows on your roof, blackout and isolated curtains or getting shade from bushes or trees. In many passive solar design houses you´ll find these measures.

Rule_4: Trees or trellises

Trees or trellises with vines or other plants provide another great and natural obstacle for the sun to heat up a passive solar design house. The temperature difference between the in- and outside of the house can run up to 20 degrees if the eastern and western windows if you are not provided with sufficient shade.

Rule_5. Trees losing leaves in winter

Trees, especially those that lose their leaves in winter, are excellent to provide shade in the summer and let the sunbeams pass through in winter to warm up a passive solar design house. An additional benefit of trees is that they serve as a gigantic overhang as they provide shade to the roof and keep the sunlight from heating up your attic. Don´t let those trees shade your solar panels though!

According passive solar design principles, it´s important to get overhangs and provide shading to keep the sun from hitting on your windows in summer. At the same time getting in as much sunlight possible in winter, is something you can realize with a wide variety of measures like canopies, trees or trellises. Your payback period of these measures as they are applied frequently in passive solar designs, is very reasonable.