Most US windows are installed flush mounted or an "outie" window. I've been reading on GBA that a recessed window or an "innie" install actually provides better U-Value's because the window is more protected. 

Journal of Light Construction

Green Building Advisor


For a roof that has a 24" overhang and if one utilizes a window install that is an "innie" install, or one that sets the window deep within the wall towards the interior (12" thick wall). Let's say the window is recessed 8" from the exterior wall surface. Would one add this 8" to the total roof overhang equation?

24" roof overhang + 8" recessed window install = 32" total overhang

The formulas I've seen do not take into account recessed window installations, only roof overhang.

are you interested in shading? If so, the best way to determine that is to draw a wall section through the window with a line representing the sun at whatever angle is pertinent. In the Passive House Planning Package worksheets the horizontal distance from the glass surface to the overhangs and from the wall/window edge are both entered, as is the veritical distance from the glass to the wall edge and overhang.

Here is a cool little program to help with overhangs and shading. http://www.susdesign.com/overhang/

cool; thanks!

Posted By Stuie on 30 Apr 2013 09:44 PM
Here is a cool little program to help with overhangs and shading. http://www.susdesign.com/overhang/

Thanks!

I'm old enough to remember when some houses had pretty little awnings over the windows that got excess sun. Put up for the summer; taken down for the winter. Of course, we had solar clothes dryers back then, too!

Posted By jdebree on 01 May 2013 05:27 PM
I'm old enough to remember when some houses had pretty little awnings over the windows that got excess sun. Put up for the summer; taken down for the winter. Of course, we had solar clothes dryers back then, too!

I remember that also. Hanging up the clothes on the clothes line and then 3 hours later, they were dry and fresh. Nowadays it's against the HOA policy to hang up clothes outside and most HOA's don't allow awnings without approval. One can say they were more "green" back then when it came to those 2 things.

I used susdesign to configure my overhangs. The sun is a 6 inch strip on the floor today.